Time at the surgical ‘coal-face’ has been reduced by introduction of the European Working Time Directive (EWTD) significantly impacting training opportunity. Our null hypothesis was that duration of surgery is significantly longer if a trainee were performing the operation despite supervision or level of trainee experience. Cemented hip hemiarthroplasty was chosen as our index procedure as complexity is largely comparable between cases. 461 patients were identified on the hospital trauma database. Data were augmented by information regarding level of surgeon, assistant and time of surgery from the hospital theatre database. There was no significant difference in registrar and consultant operative times, mean time 69 and 72 minutes respectively. SHOs were significantly slower (mean 80 minutes, p=0.0006). Junior (ST5 or less) registrars were significantly slower (mean 81minutes, p=0.0002) whereas senior registrars were not. Supervision level had no effect on duration of senior registrar operations but when junior registrars were consultant supervised they were not significantly slower (mean 75 minutes, p=0.09). Supervised operating therefore reduces time variability and should be promoted within a climate of training. Increase in mean operative time in registrars and SHOs is insignificant within a day's operating and is unlikely to lead to cancellations of cases