Venous hemodynamic studies and phlebograms of the lower limb were undertaken in 35 patients and 16 controls when clinical conditions were identified with the use of pressure bandaging. It was demonstrated that pressure dressings around the knee caused severe compression of the popliteal veins and remarkable elevation of the peripheral venous pressure in the horizontal as well as the ambulatory limb. An air splint inflated to a pressure of 15 to 20 mm Hg offered excellent compression without compromising the deep circulation. The study strongly suggests that: (1) Pressure bandaging of the knee joint retards venous circulation and may contribute to thromboembolism. It should be abandoned in favor of the "G" splint. (2) For prophylaxis against thromboembolism, elastic bandages should stop below the knee joint.