Flunitrazepam or diazepam with atropine and a combination of phenoperidine, droperidol and cyclizine (neuroleptanalgesia) were compared as premedication in three groups of 25 patients undergoing routine upper gastrointestinal endoscopy. Drug doses were titrated carefully against response and all three regimes were found to be similar in terms of safety, patient co-operation, relaxation and speed of recovery. Neuroleptanalgesia however produced a statistically significant rise in endtidal pCO2 and systolic blood pressure. The benzodiazepines, and in particular flunitrazepam, produced a significantly greater amnesia for the procedure, patients given these drugs being more willing to undergo repeat endoscopy.