International non-governmental organizations (INGOs) all over the world who seek to improve the lives of many through their various aid and development projects are all similarly interested in ensuring project longevity and sustainability. There has been rich literature on the obstacles to success and the potential remedies to them. This essay is inspired by the success of a Los Angeles-based nonprofit, The Samburu Project, whose model of partnerships with local grassroots organizations (GROs) has allowed the organization’s projects to enjoy great success. Drawing upon the experiences of The Samburu Project as well as existing literature, this essay argues that INGOs and GROs possess unique complementary characteristics that make them critical partners for project success. These characteristics include the GROs’ closeness to a given community, whose local legitimacy is a means for INGOs to bypass weak and corrupt state institutions. On the other hand, INGOs possess the necessary resources, knowledge, and global legitimacy to empower GROs and can harness the power of the international community for altruism and political pressure. Finally, the essay acknowledges the important role of the state that can either impede or facilitate an INGO-GRO partnership for program success.