A desmoid tumor of the mediastinum was diagnosed and terated in a 35 year-old white male who presented with a right supraclavicular mass. He was treated with resection, which involved several vascular structures, requiring multiple vascular reconstructions followed by postoperative radiotherapy. The authors concluded that, when located in tha mediastinum, the invasive character of such tumors and its tendency to recur may pose a considerable surgical challenge, requiring careful preoperative planing and postoperative planning follow-up. The role of radiation therapy is limited to the control of local recurrences