One hundred consecutive patients admitted to the National Spinal Injuries Centre, Stoke Mandeville Hospital, with pressure sores were studied to assess the relative importance of factors known to predispose to the development of scores. Loss of feeling was critical, because patients were unable to appreciate pain when the sore was developing. Risk of developing a sore increased with age, but duration of the paralysis was of equal importance. After discharge from hospital the presence of a caring relative or friend was essential for survival. Many patients developed sores because of poor facilities at home or inappropriate advice from those who looked after them. An even more distressing factor was the number of patients who developed sores in hospital owing to inadequate nursing care. There are relatively few paralysed patients in the community, but the lessons learnt in this study may be applied to all patients with orthopaedic injuries and to geriatric patients with limited mobility. Nursing and medical staff must turn patients regularly and ensure that there is proper equipment to relieve pressure on the skin. Patients should not be allowed to sit in a chair if they develop a sacral or trochanteric sore. More effort should be directed towards the appropriate education of patients, their relatives, and all those who are concerned with their welfare.