Thirty patients with severe and malignant arterial hypertension (AH) received 1-4 sessions (in most cases 2) of plasmapheresis to overcome refractiveness to drug therapy. Stable BP reduction, improvement of the vascular picture of the fundus of the eye and raised sensitivity to antihypertensive therapy were noted in 26 patients. Though antihypertensive drug dosages were reduced, the antihypertensive effect of plasmapheresis could be observed within 3-8 mos (an average of 5.3 +/- 0.5 mos). The efficacy of plasmapheresis was approximately equal both in symptomatic AH and in essential hypertension. Plasmapheresis was shown to be a method of overcoming refractiveness to antihypertensive therapy which could not be used alone for therapy of refractory AH. Possible mechanisms of BP reduction after plasmapheresis were discussed.