Siblings are important "peers" for children. Unfortunately, children with autism often do not play or interact often with their typically developing siblings. The purpose of this study was to teach three typically developing children (ages 4-6) skills that were likely to increase the amount and quality of social play interactions with their brothers who have autism. A teacher used the teaching interaction procedure to teach typically developing children to provide clear instructions and prompt and reinforce appropriate play behavior such as joining into a play activity, sharing toys, and engaging in appropriate toy play. All three typically developing children learned the targeted skills during role-plays with a teacher and, to a large part, generalized the skills when they played with their brothers with autism. In addition, some children who learned these skills increased their positive interactions and decreased negative interactions during a free-play period with their sibling with autism. (Contains 1 table and 7 figures.)