Academic entrepreneurship has become an increasingly important means by which universities can contribute to the economic development of a country. In Italy, universities have produced more than 700 academic spin-off companies in the last ten years. This paper uses case studies to develop an understanding of the key factors that underpin the spin-off phenomenon in the area around Milan, a region which contains three public universities and has experience of spin-off activity originating from public research dating back to the 1960s and 1970s. The role of technology transfer offices in increasing the capacity for knowledge transfer and commercial exploitation is discussed. The paper also outlines how the involvement of the financial services sector, and venture capital companies and business angels in particular, can be necessary for supporting revenue growth in academic spin-offs. (Contains 3 tables and 2 figures.)