Tumors of the inferior vena cava are rare, and most of these are leiomyosarcomas. They are most frequent in the sixth decade of life, with a female predominance. We present a 45-year-old male patient with a tumor involving the entire extent of the inferior vena cava. Computerized tomography revealed a heterogeneously enhancing mass with marked expansion of the inferior vena cava with extraluminal extension. Computerized tomography--guided biopsy of the extraluminal component showed features of a fasciculated spindle cell tumor positive for vimentin, smooth muscle actin, and calponin and negative for S-100 antigen. We discuss the clinical presentation imaging findings and review the literature.