From October 1979 to November 1984, 41 patients underwent placement of vena cava filters for prevention of pulmonary emboli. After filter placement, no pulmonary emboli were documented. No patient died due to filter placement. However, 20 of these 41 patients are dead. Eighteen deaths were caused by cancer. Ten (24%) patients died within 2 months of filter placement. Five (12%) patients died prior to hospital discharge. All ten of these patients had known, widely metastatic cancer. Among the ten patients who died more than 2 months after filter placement, six had well-differentiated, slow growing tumors. Only three of these patients had brain metastases. Among the 21 survivors only two suffered from cancer. Strict adherence to accepted indications for vena cava filter placement required operative procedures on a small but significant number of patients who demonstrated no significant improvement in quality of life or time out of hospital. Filter placement in patients with aggressive cancers and proven metastases should be performed only after analysis of predicted survival and after detailed discussions with patients and referring physicians. Filter placement in patients with aggressive metastatic cancer may cause discomfort, risk, and expense with little hope for improvement of hospital course, longevity, or quality of life.