Atracurium 0.3 mg kg-1 was given to two groups of patients to compare the recovery of spontaneous breathing with that of peripheral neuromuscular function. Anaesthesia was maintained in one group (n = 6) with an infusion of etomidate (mean flow rate 24 micrograms kg-1 min-1) and in the other group (n = 5) with 0.5% halothane. From the time of discontinuing ventilation, about 5 min after the reappearance of the tetanic response, spontaneous breathing returned in an average time of 135 s (range 18-300) in the patients given etomidate and in 68 s (range 0-123) in the patients who received halothane (ns). The duration of action of atracurium was not significantly prolonged by halothane, probably because of the low concentration used. Adequate recovery of respiratory muscle function occurred within 30 min of administration of atracurium at a time when there was less than 25% recovery of the tetanic response of the adductor pollicis muscle. It was concluded that recovery of the muscles of respiration from neuromuscular blockade by atracurium occurred more rapidly than recovery of the muscles of the hand, but an adequate tidal volume in the absence of other clinical signs should not be regarded as a reliable indicator of complete return of neuromuscular function.