Twenty-one geriatric patients (68-86 years) undergoing 30 oesophagoscopic surgical procedures received either isoflurane (mean duration 40 min), alfentanil (-methohexitone) (30 min), or propofol (30 min) anaesthesia supplemented with nitrous oxide. Each of the three study groups comprised ten patients. The times elapsing from the end of anaesthesia until the patients became irritated by the endotracheal tube, and until their tracheas were extubated, appeared similar for the groups, as did the rapidity of awakening and the ensuing grade of consciousness. During anaesthesia, spontaneous ventilation prevailed in the isoflurane group, but at recovery no inter-group differences in respiratory rate were found. There were few statistically significant differences between the groups in arterial pressure or heart rate. Only propofol prevented temporary increases in heart rate and arterial pressure.