Vascular leiomyosarcoma is a rare tumor, only about 200 cases have been reported worldwide. It commonly arises from inferior vena cava (IVC). There is a strong predilection for females and middle segment of IVC is most commonly affected. The diagnosis is often challenging as patients present with non-specific complaints such as dyspnoea, abdominal discomfort, or back pain. Computed tomography (CT) and Magnetic resonance imaging (MRI) individually or in combination with cavography, ultrasonography (US) and echocardiography, allow an early preoperative diagnosis. Here in, we present a rare case report of leiomyosarcoma of IVC in a 70 year old male patient who presented with vague abdominal discomfort. Ultrasound of abdomen detected a mass in retro peritoneum with mixed echogenicity. CT scan revealed a 10.5 x 6 x 6 cm lobulated, heterogeneously enhancing luminal mass with necrotic changes in supra-renal segment of IVC. Diagnosis of primary Vena caval tumor was made. En bloc resection of the tumor with 1 cm cuff of IVC with closure of the lower end of IVC was performed with excision of a cuff of the liver which was adherent to the IVC. Specimen grossly revealed a soft tissue mass adherent to vessel measuring 10 x 6.5 x 6 cm. External surface was smooth and bosselated. Cut section was nodular, grey white and firm in consistency. Microscopically diagnosis of Leiomyosarcoma was made. IHC study revealed positivity for Smooth muscle actin and desmin and Ki 67 positivity in 12-15 % of tumor cells and was consistent with diagnosis of Leiomyosarcoma. Key words: Desmin, Inferior vena cava, Leiomyosarcoma, Smooth muscle actin, Vascular tumor.