Préjean has performed in French film and television since the 1960s, but has been most active in dubbing. He is the primary French voice of John Lithgow and dubbed Steve Martin in The Pink Panther and its sequel. Most of his work has been in cartoons, voicing the villain "Le Nabot" in the French educational series Il Etait Une Fois... (Once Upon a Time) and characters in the Asterix movies. He dubbed Sylvester and Yosemite Sam in Looney Tunes projects, Tigger in the Winnie the Pooh franchise, Hamm in the Toy Story movies, Arthur on The Tick, Bushroot on Darkwing Duck, Capeman and various mad scientists on Inspector Gadget, and the title role on Count Duckula. Video games include Toonstruck and Star Wars: The Old Republic.