Building on the social exchange theory and displaced aggression theory, we examined the link between exploitative leadership and subordinates’ task performance via knowledge hiding. In addition, we examined the moderating effect of subordinates’ negative reciprocity beliefs. We collected multi-source and two-wave field data (N = 318 managers and employee dyads) from Malaysian service firms. We found that exploitative leadership decreases subordinates’ task performance via knowledge hiding. Moreover, this mediated link is the strongest among the subordinates scoring high on negative reciprocity beliefs. Despite the acknowledgment that organizations should focus on knowledge management, so far little is known about what causes knowledge hiding. To bridge this important gap, this study proposed and tested a research model for knowledge hiding and thus contributed to knowledge management literature.