This study examines factors that explain the creation of university spin-offs. The study focuses on mechanisms that technology transfer offices (TTOs) and universities employ to foster spin-offs. These mechanisms include technology transfer activities that support spin-offs, normative frameworks, support infrastructures (i.e., business incubators and science parks), and TTO staff's specialist technical skills. The analysis also differentiates between public and private universities. Spin-offs belong to one or more of the following groups: spin-offs with support from the university's TTO, spin-offs operating under a license agreement, and spin-offs in which the TTO or university holds equity. Qualitative comparative analysis (QCA) of 2011 data from 63 Spanish universities (46 public and 17 private) identifies recipes of antecedent conditions that effectively foster spin-offs. Results show that no unique combination of antecedent conditions yields more university spin-offs than any other does. This finding indicates that several strategies can successfully lead to academic entrepreneurship.