Organizations often claim that their actions benefit others, for example in social impact initiatives, eliciting positive legitimacy evaluations from a broad range of audiences even though such initiatives may produce limited or even harmful effects on target beneficiaries. While scholars have begun to examine relational dynamics between organizations and evaluators who render judgments about organizational legitimacy, target beneficiaries have been typically considered as the passive recipients of positive or negative impacts of organizational actions. Drawing on qualitative data from a corporate social responsibility project in Kenya, this study reveals a triadic relationship (organization–evaluators–target beneficiaries) that establishes organizational legitimacy in the eyes of evaluators while generating substantive benefits for target beneficiaries. Far from being passive, target beneficiaries actively participated in the organizational legitimation process by corroborating, in their communications with evaluators, the organization’s social impact claims. This corroboration provided leverage for the target beneficiaries to negotiate organizational support in order for them to redirect off-the-shelf practices toward contextualized practices that generated substantive benefits to themselves. Going beyond the organization–evaluator dyad, the study contributes a triadic perspective on social impact and reveals how target beneficiaries’ participation can reshape the processes and outcomes of social impact creation.