Based on social learning theory, this study explores the model of the relationship between servant leadership and customer-oriented behavior. It investigates whether the mediating role of psychological safety in linking servant leadership with customer-oriented behavior. Additionally, it verifies the boundary condition of employee self-interest concern in influencing the mediation. The moderated mediation model is tested with data from 189 service employees. The results revealed that servant leadership positively related to psychological safety, which mediated the relationship between servant leadership and customer-oriented behavior. Moderated mediation analyses further revealed that self-interest concern failed to moderate the indirect relationship between servant leadership and customer-oriented behavior.