In this paper, we propose a game-theoretic power control algorithm to minimize the total power consumption in a cooperative communication network that transmits information from multiple sources to a destination via multiple relays to save energy and improve communication performance. Under the amplify-and-forward relaying scheme, the proposed approach not only selects the best source–relay pair but also obtains the optimal transmission power, while satisfying the communication quality-of-service requirements. Using a game-theoretic model, the impacts of the number of relays on the total power consumption are also analyzed. Finally, numerical results are provided to corroborate our theoretical results and demonstrate the performance of the proposed approach.