The purpose of this study was to examine social interactions between severely autistic adolescents and mildly handicapped peers in a segregated special education setting. This was accomplished by determining (1) the frequency of reciprocal social interactions between severely autistic adolescents and mildly handicapped peers; (2) the types of social behaviors most frequently exhibited by severely autistic adolescents; (3) the levels of initiations and responses made by severely autistic adolescents and mildly handicapped peers; and ( 4) the post-intervention social behaviors of the severely autistic adolescents. Three severely autistic adolescents were exposed to a peer social initiation intervention employed by three mildly handicapped peers over a period of three months. The peer social initiation intervention was used to increase social interaction between the autistic students and their mildly handicapped peers.The research design was a multiple baseline across subjects evaluation. It was used to assess the effects of the peer intervention on each subjects' reciprocal social interactions and specific social behaviors. The independent variable was exposure to a peer social initiation intervention designed to increase social interaction behaviors. The primary dependent variable was reciprocal social interaction, which was defined as one student's positive social initiation followed by another student's positive response within 3 seconds. Results of the study were: 1. The peer social initiation intervention increased the percentage of intervals in which reciprocal interactions occurred between severely autistic students and mildly handicapped peers. 2. The peer social initiation intervention increased other vocal/verbal and other motor/gestural behaviors for the severely autistic students. 3. The levels of social responding by severely autistic adolescents increased as a result of the peer social initiation intervention. 4. Increases in reciprocal social interactions for two severely autistic adolescents generalized to a free play setting with trained and untrained peers.