This study investigated the suitability of propofol as a sole agent for continuous sedation in 100 unpremedicated patients during gastrointestinal endoscopy. The propofol was given very slowly (average 62.7 seconds) in order to prevent apnoea during induction, and the dose adjusted according to age (68% of patients were older than 50 years) and ASA grade (32% were ASA grade 3 or 4). There was no correlation under these circumstances between the observed haemodynamic variations and the age or ASA grade of the patients. The infusion rate during maintenance was also adjusted for age, and for the type of endoscopy. The mean rate was 4.3 mg/kg/hour. Recovery was rapid and of excellent quality; 77 patients were awake within 10 minutes and 99 reported total amnesia.