Entrepreneurs are surprisingly unlikely to have partners. In spite of the obvious advantages to forming partnerships, only a small minority of entrepreneurs (less than 10%, excluding family businesses) have partners. A number of possible explanations exist for this puzzling phenomenon, including an inability to locate suitable partners, fear of free-riding by partners, and a preference for not working in groups. Utilizing a diverse subject population with a high proportion of active entrepreneurs, we use a team production experiment to study whether entrepreneurs prefer to work alone or in a team. The data indicate that entrepreneurs, while no more likely to free-ride on their teammates, are substantially less interested in joining teams. This suggests that efforts to encourage partnership among entrepreneurs may run contrary to the preferences of this group.