ABSTRACT The goal of this paper is to understand better the dynamics of explicit knowledge transfers in the U.S. biopharmaceutical market sector. We draw upon the entrepreneurship and economic geography literature to help explain activity in this sector. We specifically are interested in how location and other factors affect the means, geographic distance, and knowledge base distance of these transfers. We examine explicit knowledge transfers in the form of technologies and products. We examine transfers by private and publicly traded biopharmaceutical firms using a series of binary logistic regression analyses. We find that firms located in bio-clusters are more likely to transfer explicit knowledge locally compared to non-locally. We also find that private firms compared with publicly traded firms and biotechnology firms compared to pharmaceutical firms are more likely to transfer knowledge locally. Pharmaceutical firms are more likely to transfer knowledge via licensing than product acquisitions compared with biotechnology firms. Our study should be of interest to researchers, biopharmaceutical firms, entrepreneurs, and policy makers.