Among the causes of SVC syndrome, intraluminal tumor, especially the leiomyosarcoma is very rare. We report a 39 year old female patient who had been suffering from headache and facial edema for 6 weeks before admission. On physical examination, facial edema and venous engorgement on upper extermities and upper chast wall were showed. The chest CT scan and SVC cavogram showed a long intraluminal mass lesion resulting in a near total obstruction of the SVC Surgery was performed through median sternotomy. For complete resection of the tumor and thrombus, we used partial and total CPB. The follow up SVC cavogram revealed no abnormality 14 months after the operation.