Using data from a large survey of German researchers in public science and based on a formal structure, this paper examines determinants of academic entrepreneurship. The key contribution is to discern factors driving research-driven entrepreneurship versus overall academic entrepreneurship. The extant literature has almost exclusively focused on the latter and implicitly assumed academic entrepreneurs to commercialize their research. Results show that, despite some plausible similarities in the determinants, there are significant differences. In particular, while both entrepreneurship categories benefit from greater patent applications, more time spent on consulting by the researcher and from participation in European conferences, research leaders and engineering science disciplines are more likely to lead to research-driven entrepreneurs. However, the positive influences of university employment (compared with being employed at a public research organization) on overall academic entrepreneurship fail to show up in research-driven entrepreneurship. One implication is that universities may be unduly patting themselves on the back – they might yield more entrepreneurs, but not necessarily research-driven entrepreneurs.