This project uses gender and sibling dynamics to explore the intergenerational transmission of entrepreneurship. I find that the transmission of self-employment from fathers to daughters is significantly reduced when there are sons in the family. I interpret this as evidence that the intergenerational transmission of entrepreneurship is driven, at least in part, by costly investments by parents, which can be crowded out by or redirected toward brothers. I investigate specific types of parental investments—transfers of money, businesses, and human capital—that potentially underlie this transmission and conclude that sons reduce human-capital acquisition by daughters. If all daughters of self-employed men experienced the “sisters-only” level of transmission, the overall gender gap in self-employment would be reduced by roughly 15%. This paper was accepted by Toby Stuart, entrepreneurship and innovation.