The purpose of this randomized control group study was to examine the effects of a peer network intervention that included peer mediation and direct instruction for Kindergarten and First-grade children with autism spectrum disorders. Trained school staff members provided direct instruction for 56 children in the intervention group, and 39 children participated in a comparison group. Results showed children in the intervention group displayed significantly more initiations to peers than did the comparison group during non-treatment social probes and generalization probes. Treatment session data showed significant growth for total communications over baseline levels. Children in treatment also showed more growth in language and adaptive communication. Finally, teachers’ ratings of prosocial skills revealed significantly greater improvements for the intervention group.