Summary The decision-making process in a general surgical outpatient clinic has been studied by following the course of 2000 consecutive newly referred patients of whom 1045 were put on surgical waiting lists. Surgeons were asked to record their reasons for selection for each of four levels of care: main ward, 5-day ward, day bed unit or minor outpatient surgery. Selections were influenced by social and psychological factors in 12 per cent of patients, the remaining 88 per cent were determined by the medical history or physical condition. The decision was assessed by monitoring the progress in hospital and the outcome at a follow-up clinic. In 84 per cent of patients arrangements had gone according to plan. Eleven (1·75 per cent) of 5-day or day care patients were transferred to a higher level of care and 13 (1·4 per cent) of the total series were re-admitted. Surgeons were asked to forecast the duration of postoperative stay. Thirty-six per cent were discharged on the day forecast, 63 per cent within 24 h and 75 per cent within 48 h. Forrecasts of length of stay for hernias and varicose veins were accurate but were usually underestimated for major surgery. It is concluded that for the majority of general surgical patients the selection of the level of care and the forecast of postoperative stay were sufficiently reliable to allow confident and definite advice to be given to the patient and to allow resources to be efficiently used.