Engaging the debate regarding the appropriate level of geographic diversification for multinational enterprises (MNEs), we examine a critical, yet unresolved, question: How is performance impacted by the MNE's level of intra- and inter-regional diversification versus the total level of geographic diversification? Using data from 123 U.S.-based MNEs over a seven-year period and leveraging both sales-based and subsidiary-based measures for diversification, we find that performance increases at an increasingly higher rate as firms concentrate more heavily on intra-regional diversification. Regarding inter-regional diversification and total geographic diversification, we find inverted-U relationships to exist between firm performance and the level of geographic diversification. Different from recent research on multinationality, our robustness checks indicate no evidence of a sigmoidal relationship between the degree of regional diversification and performance.