Jean-Pierre Dionnet started his career as a comics writer in Pilote in 1971. First, he had already written some articles for the comic books Futuropolis, Pogo/Poco and Phénix. His first comics work was writing short stories for such artists as Philippe Druillet, Jean-Claude Gal, Yves Got, Jacques Tardi or Jean Solé. In 1974, he wrote 'Tiriel' for Raymond Poïvet and joined the editorial team of L'Écho des Savanes, where he also wrote stories for Francis Masse and René Pétillon. A year later, he founded Métal Hurlant magazine, along with Bernard Farkas, Philippe Druillet and Moebius. He remained editor-in-chief of the magazine until 1985.
Besides his editorial activities, Dionnet remained active as a scenarist, writing stories for Jean-Claude Gal ('Les Armées du Conquérant', 'Arn') and Enki Bilal ('Exterminateur 17'). In the late 1980s and early 1990s, Dionnet wrote comics for Beb-Deum ('Région Étrangère', 'Comme un Bouquet de Violettes'), Thomas Frisano ('Art Cool'), Denis Sire ('L'Île aux Amazones'), among others. Jean-Pierre Dionnet is also active in the television world.