Inferior vena cava filters are often used as alternatives to anticoagulant therapy for the prevention of pulmonary embolism. Many of the clinical data that support the use of these devices stem from relatively limited retrospective studies. The dual purpose of this review is to examine the incidence of thrombotic complications associated with inferior vena cava filters and to discuss the role of anticoagulant therapy concurrent with filter placement. Device-associated morbidity and overall efficacy can be considered only in the context of rates of vena cava thrombosis, insertion-site thrombosis, recurrent deep venous thrombosis, and recurrent pulmonary embolism.