In order to assess the quality of sleep in surgical patients the amount of self-rated postoperative insomnia and its predisposing factors, we conducted a three-fold questionnaire * survey in 176 consecutive patients undergoing elective orthopaedic, vascular or abdominal surgery. The first questionnaire was completed the day preceding surgery, the second at the day of discharge and the third two weeks later. This survey concerned the patient's general status, his usual sleep profile and factors which could interfere with sleep (hypnotics, pain, environmental factors) throughout the study period. It allowed quantification of these parameters and the assessment of their time-course. Perioperative insomnia appeared to be a long-lasting phenomenon which persisted after discharge. Factor analysis and multiple regression models showed that postoperative, self-rated insomnia was multifactorial and mainly explained by the amount of postoperative pain (p = 0.035).