1. Thirty moderately severely hypertensive patients were studied in a double-blind comparison of minoxidil and hydrallazine in combination with frusemide and propranolol.
2. Blood pressure control in both groups of patients was satisfactory but long-term control appeared to be better in the minoxidil group.
3. Renal function was well preserved in both groups. Evidence of cardiac hypertrophy was slow to resolve despite good control of blood pressure. Side effects were negligible, and patient acceptance and rehabilitation was excellent.