The past decade has witnessed growing interests in empirically examining the effectiveness of servant leadership in management research. Our study reviews the literature on servant leadership and analyzes the relationship between servant leadership and outcome variables. Drawing on social exchange theory, this study uses meta-analysis to find that servant leadership is positively related to followers' job-related outcomes (e.g., psychological empowerment, organizational commitment, service quality), leader-related outcomes (e.g., leader effectiveness), and group-related outcomes (e.g., group service performance). Further, we find that the relationships between servant leadership and its outcomes are moderated by cultural factors (i.e., traditionality, masculinity, individualism, and power distance). Finally, we examine the incremental validity of servant leadership by taking transformational leadership into account and comparing their effects on job performance and organizational citizenship behavior (OCB) via leader-member exchange (LMX). Implications for theory and practice are discussed, and an agenda for future research is proposed.