A 76-year-old Japanese man was referred to our hospital with chief complaint of right hypochondoralgia. Abdominal ultrasound showed a retroperitoneal tumor in the suprarenal region of the right kidney. Computed tomography revealed an enhanced lobular tumor with irregular, circumscribed, and indistinct border. Ultrasound-guided biopsy was performed. The tumor consisted of spindle-shaped cells with a giant nucleus and multinuclear cells. The diagnosis was leiomyosarcoma by immunohistochemical staining. The patient underwent surgery accessed by a right eighth intercostal thoracoabdominal incision. The tumor was completely resected, accompanied by removal of the posterosuperior segment of the right hepatic lobe, right adrenal gland, and a portion of the inferior vena cava (IVC). The histopathologic diagnosis was leiomyosarcoma arising from the IVC. We present a rare case of a successfully managed leiomyosarcoma of the IVC. This case suggests the importance of curative surgical resection of the tumor due to low efficacy of adjuvant chemotherapy for leiomyosarcoma.