Myofibrosarcomas (MFSs) of the sinonasal tract are exceedingly rare tumors in adults. The principle treatment of MFS of the head and neck is surgical. However, aggressive surgery is not only debilitating, functionally and cosmetically, but tumor free margins are often difficult to obtain because of the local anatomy, and recurrence following surgery is likely. Here we report on a 64-year-old female patient who had a recurrence of an MFS of the sinonasal tract, despite prior aggressive surgery. The recurrence was successfully treated with a partial tumor resection followed by radiation therapy. To our knowledge, this is the second reported case of an MFS originating from the sinonasal tract in an adult, and the first treated with postoperative radiation therapy. This case indicates that postoperative radiation therapy may be beneficial in local disease control in such patients. However, more experience is needed to determine the efficacy of this therapeutic approach.