This study examined the effects of scripted peer-tutoring reading activities, with and without programmed common play-related stimuli, on social interactions between a kindergartner with autism spectrum disorder and his typically developing peer-tutoring partners during free play. A withdrawal design with multiple baselines across peers showed no effects of peer tutoring on social interactions. A withdrawal design with 1 peer and continuing baselines across the other 2 peers showed that adding play-related common stimuli to the peer-tutoring activity increased social interactions during free play. (Contains 1 figure.)