Abstract.Numerous scholars and practitioners claim that motivational factors can facilitate successful knowledge sharing. However, little empirical research has been conducted examining the different kinds of motivation (extrinsic and intrinsic) used to explain employee knowledge sharing behaviors. By integrating a motivational perspective into the theory of reasoned action (TRA), this study examines the role of both extrinsic (expected organizational rewards and reciprocal benefits) and intrinsic (knowledge self-efficacy and enjoyment in helping others) motivators in explaining employee knowledge sharing intentions. Based on a survey of 172 employees from 50 large organizations in Taiwan, this study applies the structural equation modeling approach to investigate the research model. The results showed that motivational factors such as reciprocal benefits, knowledge self-efficacy, and enjoyment in helping others were significantly associated with employee knowledge sharing attitudes and intentions. However, expected organizational rewards did not significantly influence employee attitudes and behavior intentions regarding knowledge sharing. Implications for organizations are discussed.