This study investigated gender differences in communication effectiveness between popular and unpopular 5- to 7-year-old children. Because previous research suggests that there may be gender differences in how popular and unpopular children communicate with each other, 24 same-gender pairs (each containing a popular and an unpopular child) were videotaped playing a game. Communication effectiveness was assessed by measuring the incidence of forms of speech associated with successful collaboration (questions, directives, and elaborations). Results revealed a popularity by gender interaction. Popular girls used a greater incidence of these forms of speech compared to unpopular girls. By contrast, there was no difference in the speech of popular and unpopular boys. Findings are interpreted in relation to the nature of the task and the characteristics of popular and unpopular children.