At the Université du Québec à Montréal, he obtained a bachelor's degree in political science, specializing in international relations.
He was a member of the executive and later the President of the Central Council of the Laurentides-Confederation of National Trade Unions.
Kieffer served as secretary and then the president of his local PQ riding executive.
He sought the open seat of Groulx in the 1994 Quebec general election and won.
Kieffer sought re-election in 2003 and lost by 303 votes to Liberal Pierre Descoteaux, in one of the tightest races that year.