The open, long-term antihypertensive, hemodynamic and metabolic effects of betaxolol in combination with furosemide and minoxidil were investigated on 30 male patients with moderate to severe essential hypertension. Twenty-three patients were observed for 104 weeks, and 7 patients for 128 weeks. The patients were seen in the clinic every 4 weeks. Blood chemistries, electrocardiograms, chest x-rays and echocardiograms were done at set intervals during the study. This drug combination caused a significant and sustained decrease in arterial pressure and heart rate (p less than 0.001), a significant increase in the cardiothoracic ratio (p less than 0.05), left and right ventricular diameter in end diastole and in left ventricular mass (p less than 0.001), and had no effect on left ventricular wall thickness, interventricular septal thickness, left ventricular ejection fraction, myocardial fiber shortening or metabolic functions. Clinical side effects included hypertrichosis, weight gain and edema. We conclude: (1) Single daily administration of betaxolol, furosemide and minoxidil produced a significant and sustained antihypertensive effect. (2) It caused cardiac enlargement and increased left ventricular mass without deterioration of myocardial function. (3) The clinical significance of the latter findings is not known at present time.