AbstractEffects of a restricted interest play activity on stereo typy, social engagement, and functional play of a preschooler with autism were evaluated in an ABAB design. Baseline free playwith peers involved high levels of stereotypy and little play and social engagement. Incorporating restricted interests de-creased stereotypy and increased play and social engagement. Effects generalized across peers and were maintained at six-weeks. Results suggest a potential approach to supporting play and social interaction in inclusive settings and extend research suggesting a relationship between play and stereotypy. KeywordsAutism.Inclusion. Restricted interests. Stereotypy. Social skills.Functional play