Fifteen autistic children, ages 4-6 years, participated in the present study. Imitation and object permanence skills were assessed. Language and social behaviors were observed during free play. Children were also exposed to three interactive procedures that differed in developmental sophistication. The experimenter either (1) simultaneously imitated the child's actions, (2) modeled a familiar action, or (3) modeled a novel action. It was found that the autistic children who had a low level of imitative ability (Piaget's Stages 2-3) were more socially responsive, showed more eye contact, and played with toys in a less perseverative manner when the experimenter imitated their behavior than when the experimenter modeled either a familiar or a novel action. When the experimenter modeled a familiar as opposed to a novel action, these children were more likely to spontaneously imitate the experimenter. The autistic children with more highly developed imitation skills, however, responded similarly to all conditions. They also were generally more socially and verbally responsive. These results suggest that developmental status is an important variable in designing intervention programs for severely impaired children.