Growth during the 1980s and 1990s in patenting and licensing by American universities is frequently asserted to be a direct consequence of the Bayh–Dole Act of 1980. However, there has been little empirical analysis of the effects of this legislation. This paper uses previously unexploited data to consider the effects of Bayh–Dole at three leading universities: the University of California, Stanford University, and Columbia University. Two of these universities (California and Stanford) were active in patenting and licensing before Bayh–Dole, and one (Columbia) became active only after its passage. The evidence suggests that Bayh–Dole was only one of several important factors behind the rise of university patenting and licensing activity. Bayh–Dole also appears to have had little effect on the content of academic research at these universities. A comparison of these three universities reveals remarkable similarities in their patent and licensing portfolios 10 years after the passage of the Bayh–Dole Act. The concluding section raises several questions about the effects of Bayh–Dole and related policy shifts that are not addressed by this analysis but that deserve attention in future research.