Sixty-five patients undergoing operation for pelvic neoplasm had prophylactic staple plication of the inferior vena cava. No fatal and only one minor nonfatal pulmonary embolism occurred. The vena cava was proved patent in 57 of 58 patients studied by vena cavagram or at autopsy. Thrombophlebitis occurred in three patients and mild edema was present in six patients postoperatively. Two operative and ten late deaths were not related to pulmonary embolism or the plication procedure. Staple plication is a rapid, safe, and effective method of providing protection against pulmonary embolism in high-risk patients undergoing abdominal operation. The late dilation of the vena caval channels seen in three of seven patients studied one to three years postoperatively does not detract from the value of the procedure.