Nine patients with normal renal function, and eight renal failure patients scheduled for renal transplantation, were anesthetized under nitrous oxide and isoflurane to determine the influence of renal function on the effect of atracurium. Atracurium 0.5 mg/kg, was given as an iv bolus, followed by 0.2 mg/kg as maintenance dose. The onset times, duration of action, duration of maintenance dose and recovery times of neuromuscular blockade were recorded and compared. There were no differences in the pharmacodynamics except that the uremic patients had slightly longer recovery time. It is concluded that atracurium is an ideal drug for uremic patients.