PURPOSE: To evaluate results of preoperative irinotecan/5-FU/leucovorin plus radiotherapy for locally-advanced rectal cancer. METHODS: Thirty-five patients with locally-advanced rectal cancer were treated with preoperative irradiation 46 Gy plus concurrent chemotherapy(irinotecan 10 mg/m(2)/d d1-d5, d22-d26, 5-FU 350 mg/m(2)/d d1-d5, d22-d26, and leucovorin 20 mg/m(2) d1-d5, d22-d26), followed by radical surgery. RESULTS: There were no treatment-related deaths. Acute toxicity was mainly in neutropenia and diarrhea, with both grade 4 neutropenia and grade 3 diarrhea observed in 4 patients(11%). Radical resectability was performed in 29 patients(83%)with sphincter preservation surgery in 7 patients. Six patients did not undergo the planned surgery due to patient refusal and disease progression. A complete pathological response was observed in 14%(4/29). Pathological T-downstaging was observed in 55%(16/29). CONCLUSIONS: These results suggest that preoperative radiochemotherapy with irinotecan/5-FU/leucovorin is safe and effective in tumor downstaging and allows sphincter-saving resection to be performed in locally-advanced rectal cancer.