Objective Controversy exists over the effects of postoperative chemoradiotherapy or chemotherapy in the treatment of rectal cancer. This study aims to evaluate the clinical effect of chemoradiotherapy or chemotherapy following radical surgery for stage Ⅱ-Ⅲrectal cancer. Methods We retrospectively analyzed the clinical data of 125 cases of stageⅡ-Ⅲrectal cancer receiving chemo-radiotherapy ( n=69) or chemotherapy ( n=56) after radical surgery. The patients in the chemoradiotherapy group were treated by 3-di-mensional conformal or intensity-modulated radiotherapy at a total irradiation dose of 45-50 Gy/25-28 times and concurrently by XE-LOX/FOLFOX chemotherapy for 4-6 cycles. Those in the chemotherapy group underwent XELOX/FOLFOX chemotherapy only, at the same dose and for the same length of time as the former. Results The therapeutic effect on stageⅡ-Ⅲrectal cancer was not correla-ted with the gender, family history, smoking history, drinking history, high-fat intake, sedentariness, obesity or constipation of the pa-tient, nor with the TNM stage, pathological grade or differentiation degree of the disease. The 1-, 2-, and 3-year survival rates were sig-nificantly higher in the chemoradiotherapy group (86. 9%, 76. 8%, and 57. 9%) than in the chemotherapy group (71. 4%, 58. 9%, and 39. 3%) (P<0. 05), while the 1-, 2-, and 3-year recurrence rates were remarkably lower in the former (5. 8%, 11. 6%, and 18. 8%) than in the latter (17. 9%, 26. 8%, and 37. 5%) (P<0. 05). Statistically significant differences were found between the che-moradiotherapy and chemotherapy groups in the incidence of diarrhea (39. 1%vs 14. 3%, P<0. 05), but not in such adverse reactions as bone marrow suppression, nausea, or vomiting (P>0. 05). Conclusion For stageⅡ-Ⅲrectal cancer, postoperative chemoradio-therapy is a safe and effective option , which can evidently reduce local recurrence and improve 3-year survival of the patient.