Leimyosarcoma of the inferior vena cava (IVC) is a rare tumor, with about 200 cases reported in the world literature. There were 5 cases reported in Korea. We report a case of primary leiomyosarcoma of the inferior vena cava in a 50 year-old woman who presented with a heterogenous enhancing mass within IVC on CT scan and MRI scan. The tumor expanded the IVC with displacement of the adjacent structures. The patient underwent ultrasound guided percutaneous biopsy which was consistent with leiomyosarcoma. The patient was treated by surgical resection and synthetic graft replacement of the inferior vena cava and postoperative external beam radiation therapy. We report the case of leiomyosarcoma of the inferior vena cava with a review of relevant literatures.