The objective of this exploratory study was to examine the interpersonal dynamics of an after-school math club for middle schoolers. Using social network analysis, 2 networks were identified and analyzed: (a) a network of friendship relationships and (b) a network of working relationships. The interconnections and correlations between friendship relationships, working relationships, and a student opinion survey were studied. We identified a core working group of students from within the network of working relations. This group acted as a central go-between for other members in the club. This core working group also expanded into the largest friendship group in the friendship network. A second group was formed from popular but aloof students who reported less impact from the club. Although there were working isolates, they were not found to be socially isolated. Students who were less popular tended to report a greater favorable impact from club participation than those who were more popular.