The relationship between biochemical failure (BF) rate and surgeon experience following open radical prostatectomy (ORP) has been well established, but BF when ORP is performed by urology trainees who are supervised by urologists of differing volume has not. We aimed to compare the oncological outcomes from ORP when a urology trainee as primary operator and is supervised by a high- or low-volume consultant urologist.Using a centralized whole of population dataset, created through the Victorian Radical Prostatectomy Registry, patients were classified as either those where a consultant was the primary operator, a urology trainee was the primary operator and supervised by a high-volume consultant or those where a urology trainee was supervised by a low-volume consultant. BF- and prostate cancer (PCa)-specific mortality was compared between these latter two groups and the consultant-only group.We found BF- and PCa-specific mortality rate to be poorer when ORP was performed by a urology trainee supervised by a low-volume consultant compared with consultant-led surgery (hazard ratio (HR) = 1.33, P = 0.022; subhazard ratio (SHR) = 2.31, P = 0.010, respectively). When a urology trainee, as primary operator, was supervised by a high-volume consultant, there was no statistical difference in BF- or PCa-specific mortality rate following ORP compared with consultant-led surgery (HR = 1.19, P = 0.234; SHR = 1.53, P = 0.346, respectively). There was a trend evident with decreasing supervisor volume leading to worse oncological and mortality outcomes for trainee-led cases.This study demonstrates the value of high-volume and fellowship-trained urologists in performing and teaching ORP. As outcomes are increasingly scrutinized with audits, the best strategy for clinicians to maintain standards and optimal patient outcomes is to understand these elements and direct trainees to appropriate centres for training and fellowships.