Arm and leg systolic and diastolic blood pressures were measured using a Doppler ultrasound technique in fifty-seven healthy male patients. The average upper limb supine blood pressure was 130/80 mm Hg. The average leg systolic pressure was 6.8 mm Hg higher than the average arm systolic pressure. The average diastolic pressure in the leg was 2.1 mm Hg higher than the average arm diastolic pressure. Agreement between pressures in opposite limbs was better than that obtained with the Korotkoff sound method. The only important difference was between supine and erect arm diastolic pressures. Electrocardiographic abnormalities were noted in six subjects; all had mild to moderate hypertension, but no overt cardiovascular disease.