The author explores effects of functional diversity on group creativity under varying group longevity. When group members have worked together for a long time in functionally diverse groups, they are expected to show stronger information processing and weaker categorization processing. Knowledge sharing and group cohesion are examined as mediating mechanisms through which functional diversity enhances group creativity as group longevity increases. Analysis of a sample of 155 workgroups demonstrates that group longevity positively moderates the relationship between functional diversity and group creativity through moderating the effects of functional diversity on two mechanisms of knowledge sharing and group cohesion.