An effort was made to determine the possible role of antihypertensive drugs in lengthening the life of patients with primary hypertension. The 58 patients satisfied rigid criteria for the diagnosis of primary hypertension, and all had had it for at least five years. They were divided into two equal, matched groups, 16 of the 29 matched patient-pairs being male. The test group received a variety of antihypertensive drugs sufficient to maintain blood pressures at or below 160/104 mm. Hg. None of these drugs were given to the contratest group. Both groups received sedatives, analgesics, digitalis, and diuretics as needed and were otherwise treated alike. Within the subsequent seven-year period of observation, 16 patients in each group died, and no significant difference between the two groups was found.