Sarcoma of the inferior vena cava (IVC) is a rare clinical entity. Surgical treatment of IVC is associated with improved survival. This case report describes a 42-year-old woman with biopsy-proven leiomyosarcoma of the inferior vena cava with intracardial tumour growth. The primary tumour was only 1 x 1 cm in the wall of the vena cava while the intracaval tumour was 12 cm long with a diameter of 5 cm and 1.5 cm in the right atrium. Using venovenous bypass with circulatory support, the tumour was excised in toto and the caval vein closed with a pericardial patch. The patient was discharged in good condition after 19 days.