We examine relations between board size, managerial incentives and enterprise performance in nonprofit organizations. We posit that a nonprofit's demand for directors increases in the number of programs it pursues, resulting in a positive association between program diversity and board size. Consequently, we predict that board size is inversely related to managerial pay-performance incentives and positively with overall organization performance. We find empirical evidence consistent with our hypotheses. The number of programs is positively related to board size. Board size is associated negatively with managerial incentives, positively with program spending and fundraising performance, and negatively with commercial revenue, in levels and changes. ► Examines relations between nonprofit board size, managerial incentives and performance. ► Finds that number of programs is positively related to board size. ► Board size is negatively associated with managerial incentives. ► Board size is positively related to program spending and fundraising performance. ► Board size and programs are negatively related to commercial revenue and positively to donations.