This study aims to investigate the effect of servant leadership on organizational citizenship behavior and knowledge-sharing behavior. It further explores servant leadership for its potential mediation of work engagement and moderation of self-efficacy in organizational citizenship behavior and knowledge-sharing behavior. Time-lagged data was collected from 264 respondents from Pakistan’s banking sector via convenience sampling. The relationships between servant leadership and organizational citizenship behavior, servant leadership and knowledge-sharing behavior were analyzed through partial least squares structural equation modeling. The results of this analysis reveals that the effect of servant leadership on organizational citizenship behavior and knowledge-sharing behavior is significant in that work engagement acts as a mediator, and follower’s self-efficacy plays the role of moderator. Based upon social exchange theory, the study supports that servant leadership increases citizenship and knowledge-sharing behavior. In addition, the study provides an understanding of how servant leadership mediates work engagement for pragmatic synergetic outcomes in a Pakistani context. The study’s implications and limitations are also discussed, and suggestions for future research are noted.