AbstractDrawing on organizational knowledge creation theory, this study examined the associations of organizational knowledge creation with employee expertise and quality of interpersonal relationships. It also examined the moderating roles of transformational leadership in explaining these relationships. Hierarchical linear modeling was performed to analyze multilevel data collected from 218 employees across 44 teams in diverse U.S. organizations. The study results indicated that employee expertise, quality of interpersonal relationships, and transformational leadership are positively associated with organizational knowledge creation. Unexpectedly, a negative moderating role of transformational leadership was found when explaining the relationship between organizational knowledge creation and quality of interpersonal relationships. It showed no moderating effect of transformational leadership in explaining the organizational knowledge creation and employee expertise relationship. The findings improve our understanding of organizational knowledge creation and enabling conditions and provide meaningful insights into the role of transformational leadership interacting with relationships in teams. The implications of these findings for research and practice are also discussed.