Leiomyosarcoma of the inferior vena cava (IVC) is a rare tumor arising from its smooth muscle cells.We report the case of a 38-year-old woman presenting with back pain and weight loss who was diagnosed with a 22-cm leiomyosarcoma of the right IVC and thrombosis of the left IVC. The patient is alive and free of recurrence a year after radical tumor resection with removal of the affected IVC, reconstruction with polytetrafluoroethylene prosthetic graft, and anastomosis of both right and left IVC.Leiomyosarcoma is a rare and aggressive tumor with a deceitful course. Radical surgical en bloc resection is the mainstay of treatment for IVC leiomyosarcomas. For an adequate restoration of venous return, complex vascular repair may be necessary.