One of the most prominent trends in organizations today is the use of teams to accomplish the work once assigned to individuals. Team composition variables, including the personality characteristics of team members, need to be carefully considered so that the transition of work from individuals to teams results in performance improvements. The types of tasks relegated to teams also affect performance, and it is equally important that group tasks are clearly defined. As such, the current study explores the impact of Big Five personality patterns on both group cohesiveness and group performance on creative, brainstorming tasks. At the group level, it was predicted that teams with personality patterns consisting of moderate levels of Extraversion, high levels of Openness to Experience, and high levels of Conscientiousness (Optimal pattern) would perform significantly better on an innovative task than teams with personality patterns that varied from this pattern. It was also hypothesized that group cohesiveness would mediate this relationship. Of the 65 three-person groups, it was found that those possessing the Optimal pattern outperformed groups with three different patterns in terms of the quantity of creative ideas generated and average level of creativity. However, groups with the Optimal pattern generated more superior ideas than only one of the other pattern conditions, and contrary to predictions, did not generate a significantly higher percentage of superior ideas than any of the other pattern conditions. It was also found that group cohesion did not mediate the relationship between group-level personality and creative task performance. The implications of these findings and directions for future research are discussed.