Research investigating contextual antecedents of employee silence remains underdeveloped. Drawing from approach-inhibition theory of power, we proposed supervisors’ power to be an important antecedent of employee silence. Guided by the perfectionism literature, we developed a moderation model in which conscientiousness and neuroticism were expected to influence the relationship between perceived supervisor power and employee silence behavior. Investigating 177 employees in different organizations, the survey results provided support for most of our hypotheses. We have empirical evidence that perceived supervisor power could have both positive and negative effects on employee silence, and such relationships were found to be stronger among less conscientious and more neurotic individuals. Theoretical and practical implications were discussed.