Given the importance of knowledge management in this competitive environment, the purpose of the present study is to fill the gap in contemporary literatures of knowledge sharing behavior and abusive supervision by observing the main effect, mechanism, and moderators. Based on social exchange perspective, we propose a theoretical model that links abusive supervision to employee knowledge sharing as mediated by leader-member exchange (LMX) with conditional processes. Employing a sample of 184 supervisor-subordinate dyads, we carried out a survey in large listed companies in South Korea. To test our hypotheses, we conducted multiple regression analyses and used bootstrapping procedures. Our results suggest that LMX mediates the abusive supervision and knowledge sharing relationship. Most significantly, findings show that this mediated relationship is contingent on the level of psychological contract fulfillment and self-enhancement motive. One of the most critical implications of our work is that negative influence of hostile behaviors of supervisors on knowledge sharing via LMX may actually be attenuated by perceptions of employees formed both from the organization (i.e., psychological contract fulfillment) and from oneself (i.e., self-enhancement motive). Moreover, it also provides practical insights for both the management practitioner and the organization. Extending from earlier studies, this research enriches our understanding of organizational behavior research by demonstrating an overall complete picture of a moderated-mediation model between abusive supervision and knowledge sharing by uncovering a mediator explaining the mechanism and moderators buffering the negative effect of abusive supervision.