Institutional scholarship on organizing in poverty contexts has focused on the constraining nature of extant institutions and the need for external actors to make transformative change interventions to alleviate poverty. Comparatively little attention has been paid to the potentially enabling nature of extant institutions in poverty contexts. We argue that more empirical work is needed to deepen our understanding of self-organizing processes that actors embedded in such contexts generate in their own efforts to survive. Drawing on the social worlds approach to institutional analysis, we shed light on how actors self-organize to produce enduring organizational arrangements to safeguard themselves against adverse poverty outcomes. Employing data from fieldwork and interviews collected in the urban neighborhood of Dagoretti Corner in Nairobi, Kenya, we examine the colocation of 105 largely identical auto repair businesses in close spatial proximity. We find that actors leverage an indigenous institution—the societal ethos of Harambee—to enable a process we identify as “survivalist organizing.” Based on our research, we argue that survivalist organizing incorporates four interlocking survival mechanisms: cultivating interbusiness solidarity, maintaining precarious interbusiness relationships, redistributing resources to prevent business deaths, and generating collective philanthropy to avoid personal destitution. We develop a new research agenda on the institutional study of self-organizing in poverty contexts focused on strengthening rather than supplanting urbanized indigenous institutions that catalyze collective self-organizing. Funding: This work was supported by the China National Science Foundation [Grants 72091310 and 72091315].