Intra-arterial pressures and pulse wave velocities were measured in 18 subjects whose auscultatory diastolic pressures ranged from 45 to 120 mm. Hg. Various methods were used to lower the blood pressure in the hypertensive and to raise it in nonhypertensive subjects so that pulse wave velocities might be compared in all subjects at a common diastolic pressure. The pulse wave velocities were calculated for a diastolic pressure of 80 mm. Hg. No significant differences were found between hypertensive and nonhypertensive subjects. It was concluded that a defect of arterial elasticity as gauged by pulse wave velocity is not a factor in the pathogenesis of hypertension.