Achieving colonoscopy under general anaesthesia entails the problem of ambulatory-care anaesthesia, in particular because perception of patient's recovery determines to some extent the length of monitoring following colonoscopy. The aims of the study was to assess the quality of patient's recovery after a colonoscopy under general anaesthesia while using propofol, by means of psychomotor-tests. METHODS--Colonoscopy was performed in 40 patients according to the following anaesthetic protocol: induction: propofol 2 mg/kg, continuous support: propofol 10 mg/kg/h i.v. with a 50 mg bolus in case of insufficient sedation; series of 3 psychomotor-tests were performed the day before and 1 hour, 3 hours and 6 hours after colonoscopy. The 3 psychomotor-tests studied: coordination (Newman test), time-space orientation and short-term memory. RESULTS--Forty patients, 25 females and 15 males, underwent colonoscopy with general anaesthesia for an average time-period of 22 +/- 11 min. The mean dose of propofol used was 286 +/- 102 mg. Awakening was complete in all patients, according to physical criteria such as consciousness and cardiovascular status, 20 min after receiving colonoscopy. The average psychomotor-tests results over time were (as percentages of original values) (*P < 10(-3); **P < 0.05): [table: see text] At 6 hours, 35 patients (87.5%) had recovered to their original performance and at 3 hours, 30 patients (75%) retained 90% their former state as measured with 3 psychomotor-tests. Neither by age or sex nor by propofol doses used or length or anaesthesia, the study population differed significantly. CONCLUSION--Three hours after colonoscopy under general anaesthesia using propofol, 30 patients (75%) had recovered at least 90% to their initial performances. Newman test was the most disturbed but there was no predictive factor for the quality of recovery. Psychomotor-tests may be useful before authorizing early discharge after colonoscopy under general anaesthesia but other recommendations about conditions of discharge after sedation must be also implemented.