Since the 1980s, the importance of entrepreneurial activity to economic and social development in all countries and regions around the world has increased. Not surprisingly, high expectations are placed by economic agents and governments on entrepreneurship as one of the key elements to fighting the global economic crisis. The objective of this chapter is to analyze the influence of institutions on entrepreneurship, evaluating the impact of the economic crisis on that relationship. Thus, by panel data models, we show the impact of formal and informal institutions on the rate of entrepreneurship in two different scenarios: before the economic crisis (2006-2007) and during the crisis (2008-2009). In general terms, the results of the study indicate that informal institutions are more important than formal institutions for the promotion of entrepreneurship and that the impact of these institutions on entrepreneurship is more relevant during the crisis. Also, the findings indicate that the economic crisis has a positive impact on entrepreneurial activity, but that this impact is higher in countries with a lower income. This could be very useful for the design of governmental policies and strategies to help overcome the economic crisis. © 2011 Nova Science Publishers, Inc. All rights reserved.