The authors examined the effects of competition and cooperation on intrinsic motivation and performance in 4 studies. Across 3 behavioral studies that involved shooting a basketball, no differences were observed between competition and cooperation on task enjoyment or performance. However, the combination of competition and cooperation (intergroup competition) consistently led to higher levels of intrinsic motivation, and in 2 of the 3 studies, performance. In a questionnaire study, the authors replicated the positive effects of intergroup competition on enjoyment and examined process measures that might account for these effects. These findings suggest that competition and cooperation both have positive aspects and that structuring recreational activities to include both can facilitate high levels of both intrinsic motivation and performance.