Gendron, who represents Abitibi-Ouest riding, broke the record of former Liberal cabinet minister Gerard D. Levesque, who served as the member for Bonaventure riding from 1956 to 1993.
According to figures supplied by the national assembly, Gendron has served for 13,665 days — so far one more than Levesque.
The native of Val-Paradis in the Abitibi region has worked with every PQ leader, starting with Rene Levesque.
Others include Pierre Marc Johnson, Jacques Parizeau, Lucien Bouchard, Andre Boisclair and Pauline Marois, who resigned after losing the April 7 election. Stephane Bedard has been chosen as interim leader.
Liberal Philippe Couillard is the 10th premier he will have seen since first being elected in 1976.
The colourful and populist Gendron held the job of vice-premier and agriculture minister in Marois's brief minority government.
He has also overseen the education, public service and natural resources portfolios in cabinet in other PQ administrations since he first entered the legislature 37 years and five months ago.
Gendron was also speaker of the national assembly, and the PQ's parliamentary and caucus leader. He was also interim leader of the PQ following Boisclair's resignation in 2007.
At 69-years-old, Gendron hesitated before running in this year's election after a health scare when he was taken away from the legislature in an ambulance.
He jumped into the campaign after getting the green light from his doctor and went on to win his 11th consecutive mandate.