This paper reports an investigation of governance issues in Italian academic spin-offs that arise from the need to balance the powers of two categories of partner: academic inventors and external investors (such as established companies and venture capital funds). The relationship between inventors and external investors, jointly pursuing a research-based entrepreneurial opportunity, provides an interesting case for the application of the agency theory construct to define adequate corporate governance procedures. The paper has two main objectives: to analyse the governance models adopted by academic spin-offs and to ascertain whether the very nature of entrepreneurial opportunity, and the associated uncertainties that a new venture faces, influence the choice of the governance model adopted. A sample group of 30 Italian academic spin-offs is analysed and three different governance models, inventor-led spin-offs, mixed-led spin-offs and investor-led spin-offs, are defined. (Contains 1 note and 2 tables.)