Purpose : To assess the efficacy and toxicity of the preoperative radiotherapy with or without chemotherapy in locally advanced rectal cancer Methods : Forty three patients (clinically diagnosed stages above or equal to Astler-Coiler stage B2 without distant metastasis) were assigned to preoperative radiotherapy alone arm (n=16) or combined preoperative radiotherapy and chemotherapy arm (n=27). Preoperative radiotherapy of 4500 cGy to whole pel-vis +/-540 cGy boost to primary site and concurrent chemotherapy of 2 cycles of 5-FU (500 mg/$m^2$) and leucovorin (20 mg/$m^2$) were used. Fifteen patients of preoperative radiotherapy alone arm and 19 of combined arm received surgical resection after preoperative treatment. Results : During the preoperative treatment, no significant complication was developed in both groups. Pathologic results were as follows; complete remission 1, Bl 1, B2 6, C1 2, C2, 5 in preoperative radiotherapy alone arm and complete remission 2, Bl 8, B2 4, C2 3, D 2 in combined arm. Postoperative complications were delayed perineal wound healing in three patients, intestinal obstruction in three patients (one managed by conservative medical treatment, two by surgical treatment). Conclusion : The combined preoperative radiotherapy and chemotherapy arm was more effective in pathological response and lymph node negativity rate than the preoperative radiotherapy alone arm. Both the preoperative radiotherapy alone arm and the combined arm were generally well tolerated and did not result in an increased postoperative morbidity.