Prior research has produced inconsistent results on the relationship between top management team (TMT) diversity and firm performance. Drawing on the information�social categorization framework, this study is designed to investigate both the mechanism and the contextual factors underlying the relationship between TMT cognitive diversity and firm performance by examining them in a unified model so as to better understand how a diverse TMT works. Based on a multi-sourced survey of top managers from 118 Chinese firms, this study finds that team interdependence and team cohesion moderate in the linkage between TMT cognitive diversity and elaboration of task-related information. In addition, TMT's elaboration of task-related information mediates the interactive effects of TMT cognitive diversity and team interdependence on firm performance as well as the interactive effects of TMT cognitive diversity and team cohesion on firm performance.