This paper aims at investigating the relationship between knowledge sharing activities and innovation capability at both individual and organizational levels. By reviewing extensive literature, a conceptual framework is built with integrating three factors: knowledge sharing, individual innovation capability and firm innovation capability. This study applies structural equation modeling (SEM) to analyze the data collected from 392 employees working at major Vietnam’s telecommunication companies. Empirical results show that knowledge sharing including knowledge donating, knowledge collecting play an important role in improving individual innovation capability. There is no direct link between knowledge collecting and organizational innovation capability, while knowledge donating has direct positive impact on product and managerial innovation. Furthermore, the individual innovation capability acts as a mediating variable between knowledge sharing practices and firm innovation capability. Implications for academics and practitioners are provided in this study.