Angiolipoma is a rare benign soft tissue tumor, an unusual variant of lipoma, consisting of fatty and vascular components. The tumor is histologically benign and may be capsulated or locally invasive. They are located in the subcutis, usually in the lower extremity and trunk. Authors experienced a case of mediastinal angiolipoma in a 9-year-old girl. Chest roentgenogram revealed a huge soft tissue mass on left lower neck and entire left superior mediastinum. CT disclosed areas of low density mass intermixed with irregular foci of higher density. The mass extended to inferior mediastinum, and contralateral side through the retrocardiac space. The bulk of the mediastinal mass was resected but recurred over a period of three years.