Self-compassion, defined as compassion extended toward oneself, is becoming increasingly vital in modern society, where risks related to mental health are increasing due to an uncertain work environment. However, how does self-compassion affect employee performance? Although self-compassion is known to be beneficial to an individual’s psychological functioning, how it affects performance in the workplace has not yet been fully examined despite its importance. Therefore, we examine how self-compassion affects various types of employees’ work performance (i.e., task performance, organizational citizenship behaviors, and counterproductive work behaviors). Relying on the self-determination theory, we predict that self-compassion affects work performance through relatedness need satisfaction, which is a distinct mechanism from competence need satisfaction that previous literature has focused on. Two survey studies (n = 217 and 145) reveal that self-compassion has a positive indirect effect on organizational citizenship behaviors via relatedness need satisfaction, while the indirect effects of self-compassion on task performance and counterproductive work behaviors are only partially supported. In addition, conscientiousness moderated the relationship between relatedness need satisfaction and task performance. These results suggest that self-compassion may affect important work outcomes through a socially driven mechanism and have a boundary condition and potential negative consequences.