Leveraging the power of corporate social responsibility (CSR) is strategically important to corporations. Despite various studies have explored the positive effects of CSR, relatively limited attention has been devoted to investigating CSR in relation to service employees from internal marketing perspectives. Therefore, this research aims to fill this research gap by developing a conceptual model, based on social influence theory, to explain how internal CSR initiatives affect service employees’ attitudes and behaviors. This study develops and empirically tests a theoretical model that examines the impact of internal CSR initiatives (i.e., internal dissemination of and management support for CSR) on service employees’ attitudes toward an organization (i.e., employee–company identification and employee–company value congruence), which ultimately enhances their organizational citizenship behaviors (OCBs) toward customers, other employees, and the organization. Survey data from 271 front-line employees of service firms which are actively involved in CSR-related activities were examined with structural equation modeling (SEM). The results suggest that perceived internal dissemination of and management support for CSR lead to service employees’ citizenship behaviors toward customers, other employees, and the organization through the mediation of employee–company identification and value congruence. Internal CSR initiatives are highly related to service employees’ various OCBs which are beneficial to improve service performance of firms. Therefore, internal marketing dissemination should call attention to companies who devote resources to CSR activities. Also, since managers’ attitudes and behaviors trickle down to employees, service supervisors’ support of CSR activities plays a significant role in forming employees’ perceptions of firms’ CSR dedication. This study represents one of the first studies that views internal CSR initiatives as an effective internal marketing lever. In addition, the relationship between internal CSR initiative and service employees’ three types of OCBs: OCB toward customers, other employees, and the organization is proposed and tested with an empirical model, providing significant contributions.