Safety behavior is the most critical task for air traffic controllers and other air traffic safety (ATS) employees. The literature shows that one of the main antecedents for ensuring safety is leadership. Yet, the understanding of leadership within air traffic control (ATC) is very limited. Drawing on both social learning theory and social exchange theory, the current research proposes and investigates the relationship between leadership aspects and ATS employees’ safety behaviors. Data were obtained from 49 ATS employees of a European air navigation service provider (ANSP), who rated their current supervisor’s servant leadership, trustworthiness, leader-member exchange, and support for safety as well as their own safety compliance and safety citizenship behavior during one to five consecutive shifts. The results of hierarchical regression analyses showed, unexpectedly, a significant negative association between supervisors’ trustworthiness and employees’ safety citizenship behavior. None of the other hypothesized relationships was significant. These findings as well as additional findings from post-hoc interviews and open comment fields suggest that the specific ATC context may require different processes than other industries. Additionally, trustworthiness may be related to lower safety citizenship behavior, possibly because ATS employees believe trustworthy supervisors take care of everything. Although a closer additional examination is warranted, ANSPs might want to take into account difficulties associated with supervisors’ trustworthiness (download full article).