The incidence and severity of venous stasis were assessed in 195 patients followed 1 to 10 years after ligation of the superficial or common femoral veins, or of the inferior vena cava. Edema was the most common manifestation. It diminished markedly in the early postoperative course. Surprisingly, it was greater after superficial femoral vein ligation. Edema and other stasis effects were most frequent and lasting after caval ligation. Seven instances of nonfatal pulmonary embolism occurred after 27 ligations at superficial femoral level, 8 after 144 at common femoral level, 4 after 15 unilateral superficial and contralateral common levels and none after caval ligation. Ligation for thromboembolic disease should be performed at common femoral or caval levels.