This is a case presentation of a patient with a primary leiomyosarcoma of the inferior vena cava. The patient's presentation and the diagnostic workup (including CT scan and vena cavagram) are reviewed. The operative procedure details the exposure of the mid-IVC, the resection of the tumor, and the reconstruction of the cava using externally supported polytetrafluoroethylene. The histology of the tumor is demonstrated, and original sketches addded for clarity.