The working hours of surgical trainees are a subject of international debate. Excessive working hours are fatiguing, and compromise performance, learning and work-life balance. However, reducing hours can impact on continuity of care, training experience and service provision. This study defines the current working hours of Australasian trainees, to inform the working hours debate in our regions. An online survey was conducted of all current Australasian trainees. Questions determined hours spent at work (AW) and off-site on-call (OC) per week, and roster structures were evaluated by training year, specialty and location. The response rate was 55.3%. Trainees averaged 61.4 ± 11.7 h/week AW, with 5% working ≥80 h. OC shifts were worked by 73.5%, for an average of 27.8 ± 14.3 h/week. Trainees of all levels worked similar hours (P= 0.10); however, neurosurgical trainees worked longer hours than most other specialties (P < 0.01). Tertiary centre rotations involved longer AW hours (P= 0.01) and rural rotations more OC (P < 0.001). Long days (>12 h) were worked by 86%; median frequency 1:4.4 days; median duration 15 h. OC shifts of 24-h duration were worked by 75%; median frequency 1:4.2 days; median sleep: 5-7 h/shift; median uninterrupted sleep: 3-5 h/shift. This study has quantified the working hours and roster structures of Australasian surgical trainees. By international standards, Australasian trainee working hours are around average. However, some rosters demand long hours and/or induce chronic sleep loss, placing some trainees at risk of fatigue. Ongoing efforts are needed to promote safe rostering practices.