A lawyer and a member of the Christian democratic Popular Republican Movement (MRP), he was elected deputy of département Bas Rhin in 1945.

With his personal roots in Alsace, Pflimlin numbered among his MRP party colleagues the Luxembourg-born Robert Schuman; for both, relations with Germany played an important role in their political thinking.

At this point the leading politicians deserted him, including Guy Mollet, Vincent Auriol, and Antoine Pinay.

The crisis culminated in a coup d'état in Algiers that was resolved with his resignation, thus facilitating Charles de Gaulle accession to the post of Prime Minister on 1 June.

The Pierre Pflimlin bridge over the Rhine south of Strasbourg, connecting France to Germany, is named after him and was opened in 2002.