In an attempt to develop a noninvasive test to assess objectively the magnitude of venous valvular dysfunction in pathologic states, photoplethysmography (PPG) was compared to venous pressure in the saphenous vein at the ankle. Simultaneous venous pressure and PPG recordings were taken before, during, and after exercise with subjects in the sitting position. In a total of 338 paired measurements in 24 normal, 25 postphlebitic, and 14 varicose limbs, PPG and venous pressure tracings appeared to be identical; data points had a correlation coefficient of great significance (r = 0.898). Postexercise recovery times clearly separated the normal from the postphlebitic limbs. Varicose limbs were assessed accurately regarding results of proposed surgery using an above-knee tourniquet. It appears that the PPG evaluation provides information comparable to venous pressure studies and does so more quickly and noninvasively. The test holds promise in measuring results of direct venous reconstructive surgery as well as in venectomy procedures.