120 high risk patients who underwent prophylactic inferior vena cava clipping were retrospectively evaluated to determine the incidence of post clipping leg swelling and pulmonary embolism. Each one of those patients had at least two criteria for the clipping. These criteria of high risk factors were precisely identified. There were two patients who had postoperative pulmonary embolism but none of them was fatal, i.e. less than two per cent. Two patients developed severe leg swelling (less than two per cent) and six had mild leg swelling (less than six per cent). Prophylactic inferior vena cava clipping is a safe and effective mean to prevent post-operative pulmonary embolism.