Recurrent pulmonary emboli occurred in 26 of 85 patients (31%) after inferior vena caval interruption to prevent pulmonary emboli. Sequelae following this procedure included early problems associated with bleeding, venous thrombosis, the sequestration syndrome, and death. Late sequelae were recurrent episodes of venous thrombosis, the post-phlebitic syndrome and recurrent emboli. Inferior vena caval interruption is associated with significant continuing disability, and it fails to solve the problem it was designed to prevent.