One hundred nine patients with moderately severe hypertension and 12 patients with severe hypertension received the combination of 50 mg. of chlorthalidone plus 0.25 mg. of reserpine combined in a single tablet (Regroton) administered once daily for an average duration of 2 years.The ease of administration (one tablet daily), the effectiveness (78-per cent good response), the lack of development of drug resistance over a 2-year period, and the small incidence of side effects would seem to make the combination of 50 mg. of chlorthalidone plus 0.25 mg. of reserpine the ideal treatment for most patients with hypertension. If a more rapid reduction in arterial pressure is indicated, as in patients with severe hypertension, or if a satisfactory therapeutic response has not been observed in 3 to 4 months in patients with moderately severe hypertension, suboptimal doses of other antihypertensive agents may be added.