Russian media reports said Ardzinba died in a Moscow clinic today.
He was named head of Abkhazia in 1990, before the collapse of the Soviet Union, and then led the region into war with Tbilisi.
In 1992, Abkhazia, led by Ardzinba, proclaimed its independence.
Ardzinba was elected president of the breakaway region in 1994, winning a second term in 1999. He resigned in 2004 due to deteriorating health.
Russia recognized Abkhazia, and another breakaway Georgian region, South Ossetia, as independent following its war with Georgia in 2008.
compiled from agency reports