Surveys of current and potential entrepreneurs suggest that obtaining adequate access to capital is one of the biggest hurdles to starting and growing a new business. Given the important role that entrepreneurship is believed to play in the process of creative destruction – and hence economic growth – it is not surprising that attempts to alleviate financing constraints for would-be entrepreneurs is an important goal for policy makers across the world. This article reviews two major streams of work examining the relevance of financing constraints for entrepreneurship. The first research stream considers the impact of financial market development on entrepreneurship. These papers usually employ variations across regions to examine how differences in observable characteristics of financial sectors (e.g., the level of competition among banks, the depth of credit markets) relate to entrepreneurs’ access to finance and realized rates of firm formation. The second stream employs variations across individuals to examine how propensities to start new businesses relate to personal wealth or recent changes therein. The notion behind this second line of research is that an association of individual wealth and propensity for self-employment or firm creation should be observed only if financial constraints for entrepreneurship exist.