The antihipertensive effect of a diuretic (dihidrochlorothiazide 100-200 mgr.), a betablocker (propranolol 20-180 mgr.) and the vasodilating agent minoxidil (25-70 mgr.), administered daily during 10-16 weeks, was asessed in 18 patients with refractory arterial hypertension (RAH). The arterial blood pressure (mm. of Hg.) differences obtained at the end of a 2 weeks diuretic period and at the end of the triple theraphy period was --53.1 +/- 18.1, p less than or equal to 0.001 (mean, standard deviation and significance) and --26.5 +/- 11.8, p less than or equal to 0.001, for clinostatic sistolic and diastolic pressures, respectively and --45.7 +/- 24.1, p less than or equal to 0.001 and --21.6 +/- 40 (p less than or equal to 0.001) for orthostatic sistolic and diastolic pressures, respectively. 66.6% of cases normalized the blood pressure at the end of the protocol. No significant changes were observed in body weight and pulse rate. In 94.4, 66.6 and 16.6% of cases appeared hypertricosis lanuginosa; edema or palpitations, respectively, as theraphy related symptoms. RAH is an entity of poor prognosis and difficult therapheutic management. In this study a significant antihipertensive response was achieved, which was superior to the one obtained in a similar population treated with other regimens in the same clinic. Despite the opposed attitude to continue the treatment exihibited by most female patients, we believe that minoxidil has enriched the therapheutic armamentarium of this dreadfull type of hypertension.