Voice behavior has been widely recognized as beneficial to organization. Accordingly, the determinants of voice behavior, such as leadership and employee characteristics, have received much research attention over the past few decades. On the other hand, researchers in leadership area have taken interested in servant leadership; however, few of them have linked it to employee voice behavior. In light of this, this study aimed to examine the effect of servant leadership on follower voice behavior. Drawing on social exchange theory, we examined the mediation role of leader-member exchange (LMX) in this relationship to clarify the mechanism through which servant leaders may promote follower voice behavior. Moreover, we also examined the moderation role of learning goal orientation to specify the boundary conditions of servant leadership effectiveness. Survey questionnaires were distributed among employees of six companies located in Zhejiang Province. Separate questionnaires were distributed to followers and their supervisors. Followers responded to survey questions on servant leadership, LMX and learning goal orientation. Followers’ immediate supervisors evaluated their voice behavior. The final sample consists of 191 employees and 42 supervisors. Hierarchical Linear Modeling was employed to test mediation and moderation hypotheses. Results showed that servant leadership was positively related to follower voice behavior, and LMX fully mediated this relationship. In addition, learning goal orientation moderated the relationship between LMX and voice behavior, such that the relationship was stronger among employees with high level of learning goal orientation. Finally, moderated mediation analyses showed that LMX mediated the relationships between servant leadership and voice behavior only for employees with high level of learning goal orientation. This study contributes to literatures on both servant leadership and voice behavior in several ways. First, this study extends our understanding of servant leadership effectiveness by examining its effect on follower voice behaviors. Second, within a social exchange framework, this study examined the mediation role of LMX in the relationship between servant leadership and follower voice behavior. The finding provides empirical evidence that servant leaders may establish social exchange relationships with their followers, through which they promote follower voice behavior. Third, this study reinforces Detert and Edmondson’s (2011) suggestion that researchers should adopt the interactional approach to examine the effects of individual and contextual factors on voice behaviors jointly. Results showed that highly learning oriented employees were more likely to fulfill their obligation to reciprocate servant leaders by performing voice behavior.