Recently, researchers across different disciplines have taken increased interest in the study of digit ratio (2D:4D), a sexually dimorphic trait used as a marker of the prenatal influence of testosterone on the cerebral development (Manning, 2002). The field of 2D:4D research has generated a number of interesting findings suggesting that this area of research may be relevant to entrepreneurship. Previous studies found more masculine finger length ratios being positively associated with dominance (Neave et al., 2003), aggressiveness (Bailey & Hurd, 2004), assertiveness and competitiveness (Wilson, 1983), and risk-taking behaviour (Garbarino et al., 2008). Moreover, Weis et. al (2007) identified relationships between 2D:4D and interests in enterprising professions. Building on these findings, we assume a positive relationship between masculine finger length ratios and entrepreneurial success. We argue that a better fit between 2D:4D ratio and career choice increases venture performance. We further test interaction effects of 2D:4D and need for achievement on business success, assuming that need for achievement produces higher relationships with success the lower - and thus more masculine - the entrepreneurs' digit ratios.