• The apparent incidence of hypertension in pregnancy among the patients in one hospital from 1941 to 1944 was 87 per 1,000; the comparable figure for the period 1951 to 1954 was 47. General improvement in prenatal care and limitation of sodium intake in particular are considered as plausible explanations. The course of pregnancy in nine patients with toxemia, eight with hypertensive vascular disease, and four with both conditions is analyzed with special reference to the effects of protoveratrine. This drug, injected intravenously in doses of 0.12 mg. or administered slowly by intravenous infusion, gave prompt reductions of blood pressure and was found to have certain advantages over other hypotensive drugs now in use. Four case histories give details illustrating the effects of oral as well as parenteral administration of protoveratrine.