The ability to manage knowledge within an organization is a critical capability that determines survival in a dynamic business environment. However, in an organization composed of diverse generations, age-based stereotypes can bring various forms of conflicts, which may hinder effective knowledge sharing among employees. Drawing on social capital theory, this study examines the effects of age stereotypes (young and old) on knowledge sharing intention through social capital factors, including reciprocity, commitment, trust, and teamwork. Among them, reciprocity, commitment, and trust are categorized as relational dimension of social capital, while teamwork represents cognitive dimension of social capital. The data were collected through a survey conducted with 141 Korean employees. The results indicate that positive age stereotypes are positively related to commitment and trust, which in turn are positively associated with knowledge sharing intention. In contrast, the perceptions of reciprocity and teamwork do not show a significant relationship with knowledge sharing intention. These findings suggest that social capital factors that are significantly associated with both types (young and old) of positive age stereotypes are positively linked to knowledge sharing intention.