Team-based activities have become commonplace in many organizations. Research on team effectiveness has included studies on the effect of several variables, including goals, reward systems, team composition, type of task, and norms conducive to innovation. These all can be seen as the context for a team's ability to develop and learn. This article extends the existing research by briefly reviewing two dominant theories of team development and learning (the stages of development model and the punctuated equilibrium model) and then proposes, using seven propositions, a synthesis of the two models, showing how they need to interact to ensure optimal team effectiveness. Several implications for human resource development are identified.