The purpose of this study was to examine the effectiveness of intensive interaction during interactive play between a preschool boy with autism and his teacher and, as a consequence, improve the social interaction between the boy and a non-autistic girl in an inclusive class in Greece. A single subject ABA design was applied. Observed variables included changes in the frequency of initiations and responses of the two children. Results indicated significant improvement and post-training maintenance in the social interaction of the two children. Discussion of results in light of known research in autism is highlighted and implications are discussed. (Contains 5 figures and 2 tables.)