Individuals with autism spectrum disorders (ASD) often have difficulties initiating and maintaining reciprocal conversations with others. In this study, we examined if an interdependent group contingency would improve reciprocal conversation of children with ASD when they were paired as conversational partners. We also assessed children's social preference through their choices between spending time with their peers or by themselves. In a multiple-baseline design, we found that the group contingency immediately produced independent reciprocal conversational responses, sustained conversational exchanges, and increased preference for peers across all participants. Improvements were further maintained even after the group contingency was removed and novel peers were introduced.