We reviewed the clinical records of 14 cases who received neoadjuvant chemoradiotherapy(CRT)to evaluate the clinical effectiveness of the CRT for T4b rectal cancer. The preoperative radiotherapy consisted of 40-50 Gy delivered in fractions of 1.8-2.0 Gy per day, 5 days per week. A treatment with intravenous 5-fluorouracil, or oral tegafur-uracil(UFT)with l-leucovorin, or oral S-1, or capecitabine or intravenous irinotecan with oral S-1, was administered during radiotherapy. One patient died due to pelvic abscess at 69 days after CRT. Complete response(CR)or partial response(PR)was observed in 8 cases, 1 month after CRT. Curative surgery was performed in 10 patients. Among 10 patients who underwent curative surgery, both urinary and anal function were preserved in 5 patients. Although no lymph node metastasis was found in 9 patients of 10 patients who underwent curative surgery, recurrence was found in 5 patients, and local recurrence was found in 4 of these patients. Recurrence occurred in all patients who had recurrence within 1 year. Preoperative CRT was expected to be an effective treatment to improve the resection rate and prognosis for T4b rectal cancer. However, it was thought that it was necessary to be careful about local recurrence, especially within 1 year after surgery.