The purpose of this paper is to examine the role of contingency variables in order to integrate the conflicting claims of prior studies regarding the effect of top management team (TMT) diversity on firm performance. To this end, the study analyzed the moderating effects of "environmental uncertainty" as an external organizational contingency variable and "TMT colocation" as an internal organizational contingency variable on the relationship between TMT diversity and firm performance. The empirical results showed that the effect of TMT diversity on firm performance was more positive in dynamic environments than in stable environments, and in situations where TMT members work together at the same location rather than in situations where they work far apart from one another. The implications of these findings and directions for future research were discussed.