Purpose - This study attempts to identify the factors and relationships that influence community of practice (COP) members' knowledge-sharing attitudes, intentions, and behaviors. Design/methodology/approach - The Theory of Planned Behavior model, Motivation Theory and the Triandis model were employed here. For the empirical validation, 282 responses from four Korean companies were collected. Findings - Whereas both extrinsic motivational and intrinsic motivational factors positively influenced attitude toward knowledge-sharing behaviors, intrinsic motivational factors were more influential in this regard. Additionally some differences in knowledge-sharing mechanisms were noted between formally managed CoPs and informally nurtured CoPs. Research limitations/implications - Since the survey samples used herein were limited to Korean companies, the results of this study may prove ungeneralizable. Practical implications - For managers who intend to introduce CoPs to their firm, a CoP supportive environment must be created, such that the image, reciprocity enjoyment of helping, and need for affiliation of each CoP member can be satisfied. Originality/value - This study is one of the first pieces of integrative research regarding CoPs to target understanding of the most crucial component of CoP activities, namely knowledge sharing.