The case of a 47-year-old man with a tumor of the posterosuperior mediastinum is reported. Surgical biopsy sample revealed a hemangiopericytoma, but radical excision was impossible because of massive bleeding. Percutaneous embolization of mediastinal tumor was performed to reduce peroperative blood loss. It allowed uneventful complete removal of the lesion. We recommend preoperative embolization in cases of hypervascular mediastinal tumors.