Various individual and organizational factors influencing employees’ knowledge contribution to electronic repositories have been identified but their effects often vary across employees and studies. This study proposes that examining the fit between employees and their organizations may explain the variations. Analysis of data from a survey of 211 employees using polynomial regression and response surface methodology indicates that when employees’ ideals about the level of skill variety, task identity, organizational innovativeness fit with those in their organizations, they develop strong commitment and engage in more knowledge contributions. In contrast, person-environment (PE) misfit in these aspects (i.e., shortfall or excess) has deleterious effects. Interestingly, excess in job autonomy, task significance, and generalized trust does not have negative impact. The PE fit theory accounts for both employee-side and organization-side effects and enriches our conceptual understanding of the antecedents of knowledge contribution. It also highlights new directions for promoting knowledge contribution in practice.