 Born in Semur-en-Auxois, Côte-d'Or, Patriat graduated from École nationale vétérinaire d'Alfort (ENVA) in 1968.He joined the Socialist Party (PS) in 1974 and was elected to the General Council of Côte-d'Or for the canton of Pouilly-en-Auxois in 1976, a position he retained until 2008.In 1981, he was elected to the National Assembly.