One hundred general surgical patients were subjected to a form of personality assessment (Eysenck and Eysenck, 1964) the day before operation. Anaesthesia was standardized using light general anaesthesia, a muscle relaxant and controlled ventilation. The day after surgery patients filled in a standardized postoperative questionnaire about complaints concerning their visit to theatre. The patients were more “neurotic” (had higher N scores) than the general population; they also had a higher lie (L) score, and this tended to increase with age. The N score was greater in those awaiting upper abdominal operations than in those awaiting other procedures, and greater in females than in males. Pain was the most conspicuous postoperative complaint, despite the use of conventional analgesia. Preoperative anxiety was also prominent, as were complaints related to the passage or presence of a nasogastric tube. There was a positive correlation between N score and complaints of anxiety, and between N score and total number of complaints, but not between N score and complaints of pain.