The entrepreneurship literature has identified several entrepreneurial traits as being important to become a successful entrepreneur. Using the Five Factor personality model we analyze differences between two types of entrepreneurs: Individuals founding an enterprise out of university employment and graduates who are not employed at the university before starting a company. To analyze potential differences in personality between these two groups we use a unique data set of former students from a large German university. We show that entrepreneurs out of the university context possess lower levels of openness to experience as well as higher levels of agreeableness. Also, we provide evidence for the importance of the predominant type of knowledge upon which academic ventures are built. The findings confirm that entrepreneurs out of the university context overly focus on the scientific aspects of their start-up idea and thus may pursue it in a potentially suboptimal manner, but that this can be mitigated by dedicated support measures and structures within the university, for which we also provide specific examples.