The present study assessed the frequency and patterns of play duration and verbal behavior of medicated attention deficit-hyperactivity disorder (ADHD) boys in an initial social encounter with a normal, same-age peer. Eight pairs each of previously unacquainted ADHD/normal boys and normal/normal boys were videotaped as they interacted in a free-play setting (N = 32). The ADHD/normal dyads engaged in more solitary play and less associative play than the normal/normal dyads. Sequential analyses of the ADHD/normal dyads' play patterns revealed that they had problems in their progression along the play hierarchy, in sustaining associative play, and in avoiding withdrawal after rough and tumble play. In comparison to the normal/normal dyads, the ADHD/normal dyads also differed in the quality of verbal interaction as seen in their lower levels of verbal reciprocity and affective expression. Process explanations for the problems ADHD boys display in an initial social encounter and the implications of these difficulties for diminished socialization opportunities were discussed.