The university economics professor was named prime minister by President Valery Giscard d'Estaing in 1976, and served until 1981 when Francois Mitterand's Socialists came to power. Barre replaced Jacques Chirac, who resigned over disagreements with Giscard d'Estaing.
He first sought treatment for heart problems in Paris in April, Euronews.net reported.
Barre was first elected to parliament in Lyon in 1978, and was considered a tough-talking politician who cut thousands of jobs in the coal and steel industries that were losing money at the time.
He was born on the French Indian Ocean island of Reunion in 1924 and moved to France to study law in 1946.
Barre is survived by his wife and two sons.