Recovery from anaesthesia with Althesin, nitrous oxide, oxygen and halothane was assessed in 29 female patients undergoing minor gynaecological surgery using an audiovisual reaction time test. A further 29 female patients not undergoing anaesthesia or surgery were subjected to the audiovisual reaction time test at similar time intervals as the anaesthetised group. The mean reaction time was significantly greater at 40 min after induction (p < 0.01) and equal to the pre-anaesthetic value at 100 min after induction. Similar decreases in mean reaction times in both anaesthetised and control subjects occurred at between 100 and 160 min which presumably reflects a learning effect, but this change was not significant.