The organization of corporate social responsibility (CSR) initiatives deals with a “make” or “buy” trade-off among in-house solutions instead of a partial (collaboration) or total (outsourcing) externalization of such activities. This article aims to advance the knowledge of the criteria underlying the governance modes of CSR. In particular, integrating the organizational economics with the insights provided by the stakeholder management, the study deepens the reasons why primary stakeholders, such as human resources (HR) and customers, may affect the choice to internalize the governance of CSR projects. Findings are consistent with the theoretical framework. In fact, internal solutions are more likely for CSR initiatives addressed to HR and customers. Given the direct linkage of these stakeholders with the achievement of the company’s mission, results corroborate the concept of closeness of CSR actions with respect to the firm’s core business as driver of in-house projects.