The present study examines the mediational role of collective engagement in the relationship between team cohesion and team creative performance. A reciprocal process was expected to unfold across creativity task episodes: (a) team cohesion leads to collective task engagement, which in turn has a positive effect on team creative performance (perceived team performance and independently rated creativity), and (b) perceived team creative performance predicts the development of future team cohesion. The study relied on a longitudinal three-wave research design through an organizational simulation exercise, in which 118 project teams (605 individuals) were charged with three creativity tasks. This study advances collective task engagement as an important mediational process explaining team performance in creative activities.