What makes teams creative? We investigated how the diversity and agreeableness of team members moderate the relationship between creative self-efficacy (CSE) and innovative performance at the team level. We found that the educational background diversity is a critical factor to affect the knowledge, perspective, and problem-solving skills and, in turn, has a positive effect on innovative performance. We also showed that the relationship between aggregated CSE and innovative performance was not linear but inverted U-shaped at the team level. We expect our study to provide meaningful managerial implications about team composition and team innovative performance.