A growing body of evidence suggests long work hours adversely affect mental health across a variety of domains. Mental health issues have been found to negatively affect work performance. This finding was highlighted in the aviation industry by the 2015 Germanwings incident in which 150 people died. Further investigation into work hours and their associated factors (e.g., demographic characteristics and experiences of sleep and fatigue in the cockpit) contributing to mental health issues among pilots is warranted. A cross-sectional survey investigating attitudes and experiences of fatigue was developed and distributed to commercial airline pilots. Results found pilots who reported typically spending longer hours on duty per week were twice as likely to report feeling depressed or anxious. Pilots' experiences of job-related sleep disturbance and fatigue may explain why pilots who typically spend long hours on duty each week are more likely to report feeling depressed or anxious.