We have recorded systolic and diastolic blood pressure, and the intervals between the QRS complex of the electrocardiogram and the Korotkoff arterial sound at systolic and diastolic pressure (QK<sub>s</sub> and QK<sub>d</sub>, respectively), at the brachial and posterior malleolar arteries, for normal subjects in the supine, standing, or head-down positions on a tilt table. These data make it possible to calculate an apparent mean pulse wave velocity. Results indicate: (1) when the subject is supine (0°), brachial and posterior malleolar artery blood pressures are virtually identical; (2) upon standing (+ 90°), both systolic and diastolic pressures in the foot are elevated by a mean of approximately 70 mm Hg, whereas brachial artery systolic pressure is unaffected and brachial diastolic pressure is raised 7 mm of mercury; (3) conversely, in the head-down (feet-up) position (-30°) the blood pressure in the foot was decreased approximately 20 mm of mercury, whereas the brachial arterial pressure is again unaffected; (4) as one changes from the head-down to the supine to the standing positions, the mean QK<sub>d</sub> interval at the brachial artery was increased by 5 and 15 msec, respectively; (5) conversely, the arrival of the pulse wave in the leg was hastened, with QK<sub>d</sub> decreasing by 7 and then 18 msec. The effects of QK<sub>s</sub> were slightly smaller in the brachial artery but considerably larger in the malleolar artery, with a decrease of 16 msec and then 49 msec; (6) mean apparent pulse wave velocity increases from 9.1 to 10.9 to 17.6 m/sec, as one changes from – 30° to 0° to + 90°.