Recognizing the benefits of international competences for firms expanding abroad, prior research advocated the positive role of executives’ international orientation, as reflected in international experience and national diversity of top management teams (TMTs). Yet research into managerial beliefs and biases as well as research into team composition suggests potential negative consequences of TMT international orientation due to overconfidence and inefficient decision-making. Combining these two perspectives, we predicted and tested non-linear effects of TMT international orientation on firm performance following foreign acquisitions. Analyses of 1,697 deals completed by 428 UK companies over a period 1999-2008 revealed that performance benefits may only accrue to the most experienced TMTs and that the benefits from TMT national diversity wane after a relatively low threshold. These findings shed new light on when TMT international orientation may (not) improve foreign acquisition performance, beyond the impact it has on internationalization decisions themselves as documented in prior research.Economic and Social Research CouncilUCD School of Business Seed Fundin