Background: The work hours of junior doctors have been in the spotlight since the mid-1980s. Rostering and the structure of surgical units aim to balance quality and continuity of patient care with reasonable working hours. Methods: Actual hours worked during two 12-week surgical registrar rosters were compared. Compliance of each roster with fatigue recommendations was assessed with Fatigue Audit InterDyne (FAID, InterDynamics Pty Ltd, Adelaide, Australia) software. Workload was determined from an electronic prospective surgical audit. Impact of the roster change was discussed with consultants and registrars. The traditional roster started on 16 July 2007 and the fatigue-friendly roster on 14 July 2008. Results: The total number of hours worked reduced by 11% (from 5085.17 h in 2007 to 4530.85 h in 2008). Fatigue was eliminated (from 133.25 h in 2007 to 0 h in 2008). Over the 12-month period, the operative workload for the Department of General Surgery increased by 18%. FAID compliance improved from 67.3 to 91.2%. Consultant and registrar satisfaction with the new roster was high. Conclusions: Safe working hours have been achieved for surgical registrars by restructuring the surgical units and implementing a new on-call rota without a perceived effect on patient care.