The semiconductor industry has made great contributions to Taiwan’s economy in the past 20 years. Because of competitive salaries and generous fringe benefits, some famous semiconductor manufacturers have become the best choice for students right after graduation. However, such magnetic effect has gradually faded away in the face of implementation of expensive employee bonuses. In a changeable environment, sharing knowledge will maintain organizational competitiveness and improve employees’ cohesion. As the semiconductor industry is characterized by a low-wage and high-turnover rate, the incurred job insecurities and career uncertainties have begun to force employees to change their cohesion, loyalty to organizations and even to reduce their willingness to share knowledge with others. This study aims to explore the relationships among organizational commitment (OC), knowledge sharing (KS) and organizational citizenship behavior (OCB) in the Taiwanese semiconductor industry. On the basis of 428 subjects, the results show that KS has a partial mediating effect on the OC–OCB relationship.