In todays’ digital age, the way consumer interacts with other consumers as well as organization had changed dramatically. Benefited from social media development, online brand community had recognized as powerful alternative media that could contribute to overall brand success. Among others, online brand community could significantly affect brand evangelism or brand referral behaviors. As previous studies attempt to examine how members of online brand community commitment determine their brand satisfaction, loyalty and repurchase intention, this study attempts to extend the understanding on how members’ brand community commitment influenced brand evangelism. This study conceptualized brand evangelism into two constructs namely positive brand referral and oppositional brand referral. Beside, brand congruity also plays a crucial role in building brand community commitment. The study among 138 members of online brand communities revealed that brand congruity has a significant relationship on brand community commitment and brand evangelism dominated by positive brand referral. Brand community commitment also found to partially mediate the relationship of brand congruity and brand evangelism. Implication and future research direction also were highlighted at the end of this article. Key Words: Marketing, Brand Congruity, Brand Community Commitment, Brand Evangelism.