Employee silence is detrimental to organizations, and managers high in narcissism may create conditions that indirectly promote employee silence. Drawing on socio‐analytic theory, in three samples ( Ns = 79, 125, and 119), we investigated whether employees’ perceptions of manager trustworthiness mediated the relation between manager trait narcissism and employee silence, and whether this mediation was moderated by a social skill, apparent sincerity. We found that the three samples largely supported our research model. Manager narcissism lowered employees’ perceptions of manager trustworthiness, which were in turn related to increased employee silence. Whereas the effect of narcissism on trustworthiness perceptions and, indirectly, on employee silence were stronger for managers lower in apparent sincerity, these effects of narcissism were absent for managers high in apparent sincerity. Practitioner points Perceptions of manager trustworthiness are a key relational process in dyadic, leader–follower relationships; for example, as our studies show, low trustworthiness predicts employee silence about important issues that may be hampering work/organizational functioning. Furthermore, our studies show that manager trait narcissism drives employees’ perceptions of their manager’s trustworthiness, and indirectly, employee silence. The findings highlight the downsides of manager narcissism in dyadic relationships with employees, which prompts guarding against hiring and promoting individuals who are high in trait narcissism to management positions. Moreover, we find that high narcissism managers who seek to appear sincere, may be successful at mitigating the impact of their narcissism on trustworthiness and silence. The findings lead us to recommend managers to improve their sincerity impression management skills – not doing so may be particularly detrimental among those who are more narcissistic.