Abstract A vena caval umbrella was implanted in twentyeight patients for the prevention of recurrent pulmonary embolism. Eighteen of these patients were catastrophically ill at the time of reimplantation. Thirteen patients died after implantation, one from a recurrent pulmonary embolus originating in the vena cava. There have been two additional recurrent nonfatal emboli. Three of the thirteen long-term survivors had significant lower extremity edema. Our experience and that of others indicates that the inferior vena caval umbrella is comparable to other methods of incomplete interruption in terms of effectiveness, morbidity, and mortality. Its unique technical advantage is the simplicity of insertion in severely ill patients in whom abdominal surgery is undesirable.