Twenty-eight patients with resectable but tethered rectal carcinomas were treated with preoperative irradiation (EBRT) and surgical resection. The 5-year actuarial disease-free survival and local control rates of these 28 patients were 66 and 76%, respectively. Two patients have developed local failure only, 2 patients concurrent local failures and distant metastases, and 4 patients distant metastases only. All local failures occurred in areas of tumor adherence to unresectable structures (sacrum, pelvic side wall). Patients with tethered rectal tumors are at risk for local failure despite preoperative irradiation and surgical resection. To improve local control in this subset of patients, an intraoperative radiation therapy (IORT) boost is given to areas of tumor adherence at resection following EBRT.