Team reflexivity, or the extent to which teams reflect upon and modify their functioning, has been identified as a key factor in the effectiveness of work teams. As yet, however, little is known about the factors that play a role in enhancing team reflexivity, and it is thus important to develop theorizing around the determinants of reflexivity. From an applied perspective, leadership is a very relevant factor. The current study is a first step in the development of such a model, and addresses this important gap in our understanding of team reflexivity by focusing on the role of leader behavior. We examined the extent to which transformational leadership influences team reflexivity, and in turn, team performance, in a field study conducted among 32 intact work teams from nine organizations. Team members rated reflexivity and leadership, while external managers rated team performance. We hypothesized and tested a mediational model proposing that transformational leadership is related to the adoption of a shared vision by the team. This in turn relates to team reflexivity, which leads to higher team performance. Results support this model.