A liquid chromatographic method for the assay of antiarrhythmic drug amiodarone and its metabolite desethylamiodarone in human plasma or serum has been developed. The method is simple and sufficiently sensitive for pharmacokinetic studies. Amiodarone, desethylamiodarone and added internal standard L 8040 were twice extracted at various pH from serum or plasma. The extract after evaporation was reconstituted in the mobile phase and chromatographed on reversed phase Hibar LiChrosorb RP-8 column with UV detection, at 254 nm. The method is specific and can detect approximately 30 ng of amiodarone and desethylamiodarone in 1 ml of plasma or serum.