The need for competitive advantage in organizations has become the hallmark of the present knowledge era. Knowledge Management Systems (KMS) provides the platform through which such goals can be realized when supplemented with other factors. In investigating how KMS contribute to organizational performance, this study conceptualizes the antecedents facilitating the effective use of KMS and relates how the usage of KMS influences both knowledge sharing practices and social capital development. Moreover, the interaction between knowledge sharing and social capital as well as their joint effect on human capital development is explored. Lastly, the framework provides theoretical explanation of how KMS utilization contributes to organizational performance by establishing the link between human capital development and organizational performance. © 2010 IEEE.