Zviad Gamsakhurdia was born in the Georgian capital Tbilisi in 1939, in a distinguished Georgian family; his father, Academician Konstantine Gamsakhurdia (1893–1975), was one of the most famous Georgian writers of the 20th century. Perhaps influenced by his father, Zviad received training in philology and began a professional career as a translator and literary critic.

Despite (or perhaps because of) the country's association with Stalin, Soviet rule in Georgia was particularly harsh during the 1950s and sought to restrict Georgian cultural expression. In 1955, Zviad Gamsakhurdia established a youth underground group which he called the Gorgasliani (a reference to the ancient line of Georgian kings) which sought to circulate reports of human rights abuses. In 1956, he was arrested during demonstrations in Tbilisi against the Soviet policy of russification and was arrested again in 1958 for distributing anti-communist literature and proclamations. He was confined for six months to a mental hospital in Tbilisi where he was diagnosed as suffering from "psychopathy with decompensation", thus perhaps becoming an early victim of what became a widespread policy of using psychiatry for political purposes.

He achieved wider prominence in 1972 during a campaign against the corruption associated with the appointment of a new Catholicos of the Georgian Orthodox Church, of which he was a "fervent" adherent. He co-founded the Initiative Group for the Defense of Human Rights in 1973, became the first Georgian member of Amnesty International in 1974 and co-founded the Georgian Helsinki Group in 1976 (renamed the Georgian Helsinki Union in 1989). Gamsakhurdia was Chairman of this human rights organization. He was very active in the underground network of samizdat publishers, contributing to a wide variety of underground political periodicals including Okros Satsmisi ("The Golden Fleece"), Sakartvelos Moambe ("The Georgian Herald"), Sakartvelo ("Georgia"), Matiane ("Annals") and Vestnik Gruzii. He participated in the Moscow underground periodical "Chronicle of Current Events", edited by Sergey Kovalev. Gamsakhurdia was also the first Georgian member of the International Society for Human Rights (ISHR-IGFM).

Perhaps seeking to emulate his father, Zviad Gamsakhurdia also pursued a distinguished academic career. He was a Senior Research Fellow of the Institute of Georgian Literature of the Georgian Academy of Sciences (1973–1977, 1985–1990), Associate Professor of the Tbilisi State University (1973–1975, 1985–1990) and member of the Union of Georgia's Writers (1966–1977, 1985–1991), PhD in the field of Philology (1973) and Doctor of Sciences (Full Doctor, 1991). He wrote a number of important literary works, monographs and translations of British, French and American literature, including translations of works by T. S. Eliot, William Shakespeare, Charles Baudelaire and Oscar Wilde. He was also an outstanding Rustvelologist (Shota Rustaveli was a great Georgian poet of the 12th century) and researcher of history of the Iberian-Caucasian culture.

Although he was frequently harassed and occasionally arrested for his dissidence, for a long time Gamsakhurdia avoided serious punishment, probably as a result of his family's prestige and political connections. His luck ran out in 1977 when the activities of the Helsinki groups in the Soviet Union became a serious embarrassment to the Soviet government of Leonid Brezhnev. A nationwide crackdown on human rights activists was instigated across the Soviet Union. In Georgia, the government of Eduard Shevardnadze (who was then First Secretary of the Georgian Communist Party) arrested Gamsakhurdia and his fellow dissident Merab Kostava. The two men were sentenced to three years' hard labour plus three years' exile for "anti-Soviet activities". Their imprisonment attracted international attention, leading to members of the United States Congress nominating Gamsakhurdia and Kostava for the Nobel Peace Prize in 1978 (though it went to Anwar Sadat and Menachem Begin instead). Kostava was exiled to Siberia, while Gamsakhurdia was exiled to the Russian autonomous republic of Dagestan.

At the end of June 1979, Gamsakhurdia was released from jail and pardoned in controversial circumstances after serving only two years of his sentence (Kostava remained in prison until 1987). The authorities claimed that he had confessed to the charges and recanted his beliefs; a film clip was shown on Soviet television to substantiate their claim. According to a transcript published by the Soviet news agency TASS, Gamsakhurdia spoke of "how wrong was the road I had taken when I disseminated literature hostile to the Soviet state. His supporters, family and Merab Kostava claimed that his recantation was coerced by the KGB, and although he publicly acknowledged that certain aspects of his anti-Soviet endeavors were mistaken, he did not renounce his leadership of the dissident movement in Georgia. In an open letter to Shevardnadze, dated April 19, 1992, Gamsakhurdia claimed that "my so-called confession was necessitated ... [because] if there was no 'confession' and my release from the prison in 1979 would not have taken place, then there would not have been a rise of the national movement." Gamsakhurdia returned to dissident activities soon after his release, continuing to contribute to samizdat periodicals and campaigning for the release of Merab Kostava. In 1981 he became the spokesman of the students and others who protested in Tbilisi about the threats to Georgian identity and the Georgian cultural heritage. He handed a set of "Demands of the Georgian People" to Shevardnadze outside the Congress of the Georgian Writers Union at the end of March 1981, which earned him another spell in jail.

When the Soviet leader Mikhail Gorbachev initiated his policy of glasnost, Gamsakhurdia played a key role in organizing mass pro-independence rallies held in Georgia between 1987–1990, in which he was joined by Merab Kostava on the latter's release in 1987. In 1988, Gamsakurdia became one of the founders of the Society of Saint Ilia the Righteous (SSIR), a combination of a religious society and a political party which became the basis for his own political movement. The following year, the brutal suppression by Soviet forces of a large peaceful demonstration held in Tbilisi in April 4–9, 1989 proved to be a pivotal event in discrediting the continuation of Soviet rule over the country. The progress of democratic reforms was accelerated and led to Georgia's first democratic multiparty elections, held on October 28, 1990. Gamsakhurdia's SSIR party and the Georgian Helsinki Union joined with other opposition groups to head a reformist coalition called "Round Table — Free Georgia" ("Mrgvali Magida — Tavisupali Sakartvelo"). The coalition won a convincing victory, with 64% of the vote, as compared with the Georgian Communist Party's 29.6%. On November 14, 1990, Zviad Gamsakhurdia was elected by an overwhelming majority as Chairman of the Supreme Council of the Republic of Georgia.

Georgia held a referendum on restoring its pre-Soviet independence on March 31, 1991 in which 90.08% of those who voted declared in its favour. The Georgian parliament passed a declaration of independence on April 9, 1991, in effect restoring the 1918-21 Georgian state. However, it was not recognized by the Soviet Union and although a number of foreign powers granted early recognition, universal recognition did not come until the following year. Gamsakhurdia was elected President in the election of May 26 with 86.5% per cent of the vote on a turnout of over 83%.

On taking office, Gamsakhurdia was faced with major economic and political difficulties, especially regarding Georgia's relations with the Soviet Union. A key problem was the position of Georgia's many ethnic minorities (making up 30% of the population). Although minority groups had participated actively in Georgia's return to democracy, they were underrepresented in the results of the October 1990 elections with only nine of 245 deputies being non-Georgians. Even before Georgia's independence, the position of national minorities was contentious and led to outbreaks of serious inter-ethnic violence in Abkhazia during 1989. In 1989, violent unrest broke out in South Ossetian Autonomous Oblast between the Georgian independence-minded population of the region and Ossetians loyal to the Kremlin. South Ossetia's regional soviet announced that the region would secede from Georgia to form a "Soviet Democratic Republic". In response, the Georgian Supreme Soviet annulled the autonomy of South Ossetia in March 1990. A three-way power struggle between Georgian, Ossetian and Soviet military forces broke out in the region, which resulted (by March 1991) in the deaths of 51 people and the eviction from their homes of 25,000 more. After his election as Chairman of the newly renamed Supreme Council, Gamsakhurdia denounced the Ossetian move as being part of a Russian ploy to undermine Georgia, declaring the Ossetian separatists to be "direct agents of the Kremlin, its tools and terrorists." In February 1991, he sent a letter to Mikhail Gorbachev demanding the withdrawal of Soviet army units and an additional contingent of interior troops of the USSR from the territory of former Authonomous District of South Ossetia.

According to George Khutsishvili, the nationalist "Georgia for the Georgians" hysteria launched by the followers of Gamsakhurdia "played a decisive role" in "bringing about Bosnia-like inter-ethnic violence." On December 27, 1991, U.S. based Helsinki Watch NGO issued a report on Human Rights violations made by the government of Gamsakhurdia. The report included information on documented Freedom of Assembly, Freedom of Speech, Freedom of the Press violations in Georgia, on Political Imprisonment, Human Rights abuses by Georgian government and paramilitary in South Ossetia, and other human Rights violations. Gamsakhurdia's opponents were highly critical of what they regarded as "unacceptably dictatorial behaviour", which had already been the subject of criticism even before his election as President. Prime Minister Tengiz Sigua and two other senior ministers resigned on August 19 in protest against Gamsakhurdia's policies. The three ministers joined the opposition, accusing him of "being a demagogue and totalitarian" and complaining about the slow pace of economic reform. In an emotional television broadcast, Gamsakhurdia claimed that his enemies were engaging in "sabotage and betrayal" within the country.

Gamsakhurdia's response to the coup against President Gorbachev was a source of further controversy. On August 19, Gamsakhurdia, the Georgian government, and the Presidium of the Supreme Council issued an appeal to the Georgian population to remain calm, stay at their workplaces, and perform their jobs without yielding to provocations or taking unauthorized actions. The following day, Gamsakhurdia appealed to international leaders to recognize the republics (including Georgia) that had declared themselves independent of the Soviet Union and to recognise all legal authorities, including the Soviet authorities deposed by the coup. He claimed publicly on August 21 that Gorbachev himself had masterminded the coup in an attempt to boost his popularity before the Soviet presidential elections, an allegation rejected as "ridiculous" by US President George H. W. Bush.

In a particularly controversial development, the Russian news agency Interfax reported that Gamsakhurdia had agreed with the Soviet military that the Georgian National Guard would be disarmed and on August 23 he issued decrees abolishing the post of commander of the Georgian National Guard and redesignating its members as interior troops subordinate to the Georgian Ministry of Internal Affairs. In reality, the National Guard was already a part of the Ministry of the Interior, and Gamsakhurdia's opponents, who claimed he was seeking to abolish it, were asked to produce documents they claimed they possessed which verified their claims, but did not do so. Gamsakhurdia always maintained he had no intention of disbanding the National Guard. In defiance of the alleged order of Gamskhurdia, the sacked National Guard commander Tengiz Kitovani led most of his troops out of Tbilisi on August 24. By this time, however, the coup had clearly failed and Gamsakhurdia publicly congratulated Russia's President Boris Yeltsin on his victory over the putschists. Georgia had survived the coup without any violence, but Gamsakhurdia's opponents accused him of not being resolute in opposing it. Gamsakhurdia reacted angrily, accusing shadowy forces in Moscow of conspiring with his internal enemies against Georgia's independence movement. He shut down an opposition newspaper, "Molodiozh Gruzii," on the grounds that it had published open calls for a national rebellion. Giorgi Chanturia, whose National Democratic Party was one of the most active opposition groups at that time, was arrested and imprisoned on charges of seeking help from Moscow to overthrow the legal government. It was also reported that Channel 2, a television station, was closed down after employees took part in rallies against the government.

The political dispute turned violent on September 2, when an anti-government demonstration in Tbilisi was dispersed by police. The most ominous development was the splintering of the Georgian National Guard into pro- and anti-government factions, with the latter setting up an armed camp outside the capital. Skirmishes between the two sides occurred across Tbilisi during October and November with occasional fatalities resulting from gunfights. Paramilitary groups — one of the largest of which was the anti-Gamsakhurdia "Mkhedrioni" ("Horsemen" or "Knights"), a nationalist militia with several thousand members — set up barricades around the city. On December 22, 1991, armed opposition supporters launched a violent coup d'etat and attacked a number of official buildings including the Georgian parliament building, where Gamsakhurdia himself was sheltering. Heavy fighting continued in Tbilisi until January 6, 1992, leaving at least 113 people dead. On January 6, Gamsakhurdia and members of his government escaped through opposition lines and made their way to Azerbaijan where they were denied asylum. Armenia finally hosted Gamsakhurdia for a short period and rejected Georgian demand to extradite Gamsakhurdia back to Georgia. In order not to complicate tense relations with Georgia, Armenian authorities allowed Gamsakhurdia to move to the breakaway Russian republic of Chechnya, where he was granted asylum by the rebellious government of General Dzhokhar Dudayev.

It was later claimed (although apparently not confirmed) that Soviet forces had been involved in the coup against Gamsakhurdia. On December 15, 1992 the Russian newspaper Moskovskie Novosti ("Moscow News") printed a letter claiming that the former Vice-Commander of the Trans-Caucasian Military District, Colonel General Sufian Bepaev, had sent a "subdivision" to assist the armed opposition. If the intervention had not taken place, it was claimed, "Gamsakhurdia's supporters' victory would be guaranteed." It was also claimed that Soviet special forces had helped the opposition to attack the state television tower on December 28.

A Military Council made up of Gamsakhurdia opponents took over the government on an interim basis. One of its first actions was to formally depose Gamsakhurdia as President. It reconstituted itself as a State Council and appointed Gamsakhurdia's old rival Eduard Shevardnadze as chairman in March 1992. The change in power was effected as a fait accompli, without any formal referendum or elections. He ruled as de facto president until the formal restoration of the presidency in November 1995.

After his overthrow, Gamsakhurdia continued to promote himself as the legitimate president of Georgia. He was still recognized as such by some governments and international organizations, although as a matter of pragmatic politics the insurrectionist Military Council was quickly accepted as the governing authority in the country. Gamsakhurdia himself refused to accept his ouster, not least because he had been elected to the post with an overwhelming majority of the popular vote (in conspicuous contrast to the undemocratically appointed Shevardnadze). In November-December 1992, he was invited to Finland (by the Georgia Friendship Group of the Parliament of Finland) and Austria (by the International Society for Human Rights). In both countries, he held press conferences and meetings with parliamentarians and government officials.

Clashes between pro- and anti-Gamsakhurdia forces continued throughout 1992 and 1993 with Gamsakhurdia supporters taking captive government officials and government forces retaliating with reprisal raids. One of the most serious incidents occurred in Tbilisi on June 24, 1992, when armed Gamsakhurdia supporters seized the state television center. They managed to broadcast a radio message declaring that "The legitimate government has been reinstated. The red junta is nearing its end." However, they were driven out within a few hours by the National Guard. They may have intended to prompt a mass uprising against the Shevardnadze government, but this did not materialize. Shevardnadze's government imposed a harshly repressive regime throughout Georgia to suppress "Zviadism", with security forces and the pro-government Mkhedrioni militia carrying out widespread arrests and harassment of Gamsakhurdia supporters. Although Georgia's poor human rights record was strongly criticized by the international community, Shevardnadze's personal prestige appears to have convinced them to swallow their doubts and grant the country formal recognition. Government troops moved into Abkhazia in September 1992 in an effort to root out Gamsakhurdia's supporters among the Georgian population of the region, but well-publicized human rights abuses succeeded only in worsening already poor ethnic relations. Later, in September 1993, a full-scale war broke out between Georgian forces and Abkhazian separatists. This ended in a decisive defeat for the government, with government forces and 300,000 Georgians being driven out of Abkhazia and an estimated 10,000 people being killed in the fighting.

Gamsakhurdia soon took up the apparent opportunity to bring down Shevardnadze. He returned to Georgia on September 24, 1993, establishing what amounted to a "government in exile" in the western Georgian city of Zugdidi. He announced that he would continue "the peaceful struggle against an illegal military junta" and concentrated on building an anti-Shevardnadze coalition drawing on the support of the regions of Samegrelo (Mingrelia) and Abkhazia. He also built up a substantial military force that was able to operate relatively freely in the face of the weak state security forces. After initially demanding immediate elections, Gamsakhurdia took advantage of the Georgian army's rout to seize large quantities of weapons abandoned by the retreating government forces. A civil war engulfed western Georgia in October 1993 as Gamsakhurdia's forces succeeded in capturing several key towns and transport hubs. Government forces fell back in disarray, leaving few obstacles between Gamsakhurdia's forces and Tbilisi. However, Gamsakhurdia's capture of the economically vital Georgian Black Sea port of Poti threatened the interests of Russia, Armenia (totally landlocked and dependent on Georgia's ports) and Azerbaijan. In an apparent and very controversial quid pro quo, all three countries expressed their support for Shevardnadze's government, which in turn agreed to join the Commonwealth of Independent States. While the support from Armenia and Azerbaijan was purely political, Russia quickly mobilized troops to aid the Georgian government. On October 20, around 2,000 Russian troops moved to protect Georgian railroads and provided logistical support and weapons to the poorly armed government forces. The uprising quickly collapsed and Zugdidi fell on November 6.

On December 31, 1993, Zviad Gamsakhurdia died in circumstances that are still unclear. It is known that he died in the village of Khibula in the Samegrelo region of western Georgia and later was re-buried in the village Jikhashkari (in the Samegrelo region also). According to British press reports, the body was found with a single bullet wound to the head. A variety of reasons have been given for his death, which is still controversial and remains unresolved.

Gamsakhurdia's death was announced by the Georgian government on January 5, 1994. Some refused to believe that Gamsakhurdia had died at all but this question was eventually settled when his body was recovered on February 15, 1994. Zviad Gamsakhurdia's remains were re-buried in the Chechen capital Grozny on February 24, 1994. On March 3, 2007, the newly appointed pro-Russian president of Chechnya Ramzan Kadyrov announced that Gamsakhurdia's grave - lost in the debris and chaos of a war-ravaged Grozny - was found in the center of the city. The remains of Gamsakhurdia were identified by Russian experts in Rostov-on-Don, and arrived in Georgia on March 28, 2007, for reburial. He was interred alongside other prominent Georgians at the Mtatsminda Pantheon on April 1, 2007. Thousands of people throughout Georgia had arrived in Mtskheta's medieval cathedral to pay tribute to Gamsakhurdia. "We are implementing the decision which was [taken] in 2004 – to bury President Gamsakhurdia on his native soil. This is a fair and absolutely correct decision," President Mikheil Saakashvili told reporters, the Civil Georgia internet news website reported on 31 March.