Two patients in chronic renal failure receiving amiodarone for the treatment of refractory arrhythmias were commenced on dialysis, in one case, intermittent peritoneal dialysis, in the other, haemodialysis. Plasma concentrations of amiodarone and its desethyl metabolite were consistent with the dose received, whilst neither compound was recovered in the dialysate. In these patients and in 10 additional patients with normal renal function taking amiodarone, only negligible amounts of either compound were detected in urine. These findings suggest that amiodarone may be a suitable antiarrhythmic agent for use in patients with chronic renal failure.