Minoxidil in combination with propranolol and diuretics was used in the treatment of 41 patients with severe refractory hypertension due to a spectrum of causes. These etiologies included essential hypertension, advanced renal failure, renovascular hypertension, and kidney transplant rejection. All patients had evidence of renal and cardiac damage prior to therapy and had failed to respond to all standard medications. The study included patients treated for periods of 3--42 months. Forty of the 41 patients responded most impressively to this therapy. Minoxidil was given in a dose of 7.5--40 mg daily. No tolerance to minoxidil was observed. Side effects were minimal. Three myocardial infarcts were observed. Two of these patients had had previous infarcts. One patient suffered a fatal cerebrovascular accident after he had deliberately stopped all medications. Nine patients showed sodium retention, which was easily controlled in 8 cases. Mild hirsutism was occasionally seen. Mean serum creatinine levels showed a slight decrease in the essential hypertension group after treatment. Best long-term results were seen in the essential hypertension and renovascular groups, although several cases with advanced renal disease and with kidney transplant rejection hypertension showed very impressive and encouraging outcomes.