This paper considers the impact of institutions on new firm entry in emerging markets. In particular, it surveys the findings of a 2-year research project on the sources of success in terms of entry rates and conditions (including gross entry rates, exit rates and therefore net entry rates) across the BRIC countries (Brazil, Russia, India, China). These emerging market economies display widely varying entry and exit rates and a framework is developed to capture the interaction between key aspects of formal institutions, how those institutions play out in practice, and their impact on entry and exit rates. The country case studies reveal that, whilst different contingencies affect the relationships between institutions and entry in each country, there are some empirical regularities in the determinants of successful entry and conversely in its constraints. One such regularity is the critical interaction between formal rules and informal mechanisms. There is also variation in whether these works so as to compensate for deficiencies in formal institutions, as in China and India, or whether deficiencies in formal mechanisms are compounded by poor informal mechanisms, as is sometimes true in Brazil. Indeed, relatively good formal rules and structures can be undermined by informal mechanisms deterring or blocking entry, as is largely the case in Russia.