Abstract: The venous invasion from intraabdominal and retroperitoeal tumors (e.g., liver and kidney) is relatively frequent. Primary vascular (venous) tumors are uncommon. The authors review the case of a 67-year-old woman, who was admitted to the hospital in a poor general condition with jaundice. Laboratory findings indicated hepatic and renal insufficiency. Abdominal ultrasound detected a large retroperitoneal mass which was suspected to be of uterine origin. Abdominal CT showed a retroperitoneal mass that invaded the inferior vena cava, but there was no sign of primary intraabdominal or pelvic tumor. Due to the poor general condition of the patient, surgery was not performed. The patient died in some days after admission. Autopsy revealed a primary leiomyosarcoma of the inferior vena cava. Based on the literature data, primary leiomyosarcoma of the inferior vena cava is extremely rare. Leiomyosarcoma of the inferior vena cava can cause various symptoms, depending on the involved segment of the vein. Surgical intervention can be performed in early stages of the disease. In uncertain retroperitoneal tumors involving the inferior vena cava, radiologists should think of the possibility of tumor with vascular origin. Orv Hetil. 2019; 160(19): 756–761.