The recognition of facial immaturity and emotional expression by children with autism, language disorders, mental retardation, and non-disabled controls was studied in two experiments. Children identified immaturity and expression in upright and inverted faces. The autism group identified fewer immature faces and expressions than control (Exp. 1 & 2), language disordered (Exp. 1), and mental retardation (Exp. 2) groups. Facial inversion interfered with all groups' recognition of facial immaturity and with control and language disordered groups' recognition of expression. Error analyses (Exp. 1 & 2) showed similarities between autism and other groups' perception of immaturity but differences in perception of expressions. Reasons for similarities and differences between children with and without autism when perceiving facial immaturity and expression are discussed.