We analyze nearly 70 million scientific articles to estimate the gender dynamics in the commercialization of science. We report a gender gap of 14 percent, which does not appear to be explained either by the quality of the science or by its commercial potential. The gap is widest among papers with female last authors (i.e., lab head or principal investigator), even when publishing high-quality science. However, the gap vanishes when authors self-commercialize discoveries via new ventures, and the gap is reduced when commercializing in cooperation with firms that are smaller or that have more female inventors. (JEL D22, I23, J16, O31, O34)