Surgical trainees need exposure to a wide variety of operations and a chance to operate under supervision. At the same time there is the over-riding responsibility to do the best for our patients. Cardiac surgery is dominated by coronary bypass surgery and the tendency has been to delegate easy coronary cases to trainees and to neglect their experience in other areas. This paper is an audit of trainee exposure and supervision in a training centre. During a 20-month period, 35.2 per cent of cases were delegated; 20.6 per cent to the senior registrar and 14.6 per cent to the registrars. Senior registrars were assisted by the consultant in 19.1 per cent of their cases and registrars were assisted by more senior colleagues in 28.5 per cent of theirs. Most cases delegated to trainees were of low perioperative risk and operations were performed with commensurate low morbidity and mortality. The delegation of valve surgery was disproportionately low in comparison to overall case mix. On the basis of this study, the delegation of cases is being reviewed in the knowledge that with appropriate selection, trainees can gain valuable operative experience without compromising patient-safety.