Although theory suggests that testosterone should facilitate competitive performance, empirical evidence has been mixed. The present study tested the hypothesis that testosterone's effect on competitive performance depends on whether competition is among individuals (individual competition) or among teams (intergroup competition). Sixty participants (50% women) provided saliva samples and were randomly assigned to complete an analytical reasoning test in individual or intergroup competition. Testosterone was positively related to performance in individual competition, but testosterone was negatively related to performance in intergroup competition. There were no sex differences in performance or in the magnitude of testosterone-performance relationships. These results are consistent with the hypothesis that high testosterone individuals are motivated to gain status (good performance in individual competition), whereas low testosterone individuals are motivated to cooperate with others (good performance in intergroup competition). Theoretical and practical implications are discussed.