Born in Paris, Pierre Lacroix should initially take over his parents small shop in Marly-le-Roi. But Lacroix ambitions were with drawing and not commerce. Therefore, at the age of 17, he became the apprentice of Louis Forton, author of 'Les Pieds Nickelés', who was a client of the shop. Forton introduced him to the S.P.E. (Société Parisienne d'Édition) and in 1930, he started making illustrations for Le Pêle-Mêle. He subsequently made some advertising illustration artwork for clients like Gestetner.
During the 1960s, Lacroix's work also appeared in the magazines Lisette ('Mick et Mack' and 'Domi et Pascaline'), Fripounet ('Nelly'), Le Journal de Bibi Fricotin and Le Journal des Pieds Nickelés ('Razibus Zouzou', 'Les Chahuteurs'). With writer Montaubert, he made an album of 'Placide et Pomalo' and four albums of 'Coussie et Coussa' (Ed. Albon). In 1974, he drew two stories with 'Aggie' for Fillette, replacing Gérard Alexandre.