This article investigates the impacts of partnerships on three aspects of nonprofits’ human resources capacity—paid staff, volunteers, and the professional development of staff of nonprofit organizations. Analysis of the seemingly unrelated regressions (SUR) suggests that partnerships may yield some human capacity improvements, that is, increasing the number of staff and opportunities for their professional development. The number of volunteers is not affected by partnerships but rather by other financial resources. The main implication of this research is that partnerships should be formed on the basis of their comparative advantages and focused on identifying suitable partners and cultivating these relations rather than collaborating with more organizations.