OBJECTIVE--To examine the psychological impact of surgical accidents and assess the adequacy of explanations given to the patients involved. DESIGN--Postal questionnaire survey. SETTING--Subjects were selected from files held Action for Victims of Medical Accidents. PATIENTS--154 surgical patients who had been injured by their treatment, who considered that their treatment had fallen below acceptable standards. MAIN MEASURES--Adequacy of explanations given to patients and responses to standard questionnaires assessing pain, distress, psychiatric morbidity, and psychosocial adjustment (general health questionnaire, impact of events scale, McGill pain questionnaire, and psychosocial adjustment to illness scale). RESULTS--101 patients completed the questionnaires (69 women, 32 men; mean age 44 (median 41.5) years. Mean scores on the questionnaires indicated that these injured patients were more distressed than people who had suffered serious accidents or bereavements; their levels of pain were comparable, over a year after surgery, to untreated postoperative pain; and their psychosocial adjustment was considerably worse than in patients with serious illnesses. They were extremely unsatisfied with the explanations given about their accident, which they perceived as lacking in information, unclear, inaccurate, and given unsympathetically. Poor explanations were associated with higher levels of disturbing memories and poorer adjustment. CONCLUSIONS--Surgical accidents have a major adverse psychological impact on patients, and poor communication after the accident may increase patients' distress. IMPLICATIONS--Communication skills in dealing with such patients should be improved to ensure the clear and comprehensive explanations that they need. Many patients will also require psychological treatment to help their recovery.