Background Learning is in delicate balance with safety, as faculty supervisors try to foster trainee development while safeguarding patients. This balance is particularly challenging if trainees are allowed to experience the educational benefits of failure, acknowledged as a critical resource for developing competence and resilience. While other educational domains allow failure in service of learning, however, we do not know whether or not this strategy applies to clinical training.

Methods We conducted individual interviews of clinical supervisors, asking them whether they allowed failure for educational purposes in clinical training and eliciting their experiences of this phenomenon. Participants’ accounts were descriptively analysed for recurring themes.

Results Twelve women and seven men reported 48 specific examples of allowing trainee failure based on their judgement that educational value outweighed patient risk. Various kinds of failures were allowed: both during operations and technical procedures, in medication dosing, communication events, diagnostic procedures and patient management. Most participants perceived minimal consequences for patients, and many described their rescue strategies to prevent an allowed failure. Allowing failure under supervision was perceived to be important for supporting trainee development.

Conclusion Clinical supervisors allow trainees to fail for educational benefit. In doing so, they attempt to balance patient safety and trainee learning. The educational strategy of allowing failure may appear alarming in the zero-error tolerant culture of healthcare with its commitment to patient safety. However, supervisors perceived this strategy to be invaluable. Viewing failure as inevitable, they wanted trainees to experience it in protected situations and to develop effective technical and emotional responses. More empirical research is required to excavate this tacit supervisory practice and support its appropriate use in workplace learning to ensure both learning and safety.