This paper investigates the role of knowledge for successful entrepreneurship. The paper explicitly discusses the role of accessibility to university and company R&D for new firm formation. Company R&D is assumed to contain a higher share of R&D directed towards generating technological knowledge. Hence, the accessibility to such R&D are expected to have a stronger influence on new firm formation than the accessibility to university R&D. Since knowledge can also be assumed to be spatially bounded and diffuses in geographical space, it is argued that local interaction, measured by intra-municipality accessibility to knowledge, have a stronger influence on new firm formation than interregional interaction. In the empirical analysis data on new firm formation in 288 Swedish municipalities and accessibility to university and company R&D for 1997 and 1999 are used. We find that accessibility to company R&D have a stronger impact on new firm formation than accessibility to university R&D. We also find that close knowledge interactions are more important for new firm formation than long distance knowledge interactions. Accessibility to inter-regional company R&D has even a negative impact on new firm formation.