In his first film, Leonov was cast as an extra and did not receive any recognition. He later became Georgiy Daneliya's regular, appearing in all of his features, including "Gentlemen of Fortune", "Autumn Marathon", "Mimino", "Afonya" and "Kin-dza-dza!". According to the Allmovie, "his short, round stature, expressive eyes, broad and open face, slow movements, and slightly slurred speech made him ideal for the comic roles in which he specialized". But he also attracted critical notice for his tragic parts and the invariable naturalness of his acting. Many notable actors were said to avoid appearing in the same films with Leonov, for his natural manner of acting made them seem strained.