PURPOSE: Tumor response of patients with locally advanced rectal cancer after chemoradiation showed 60~70% of tumor volume reduction and T and N downstaging. Curative resection with total mesorectal excision should be followed for good oncologic outcomes. This study was designed to analyze the oncologic outcomes in patients who received preoperative chemoradiation followed by total mesorectal excision for locally advanced rectal cancer according to pathologic T and N stage. METHODS: Total 108 patients with locally advanced rectal cancer treated between 1989 and 2000. All patients were analyzed retrospectively and staged as T3, 4 N (+) by transrectal ultrasonography and pelvic MRI. All patients received a 5, 040 cGy of radiation over 5 weeks and systemic intravenous bolus chemotherapy 5 FU 450 mg/m2 and leucovorin 20 mg/m2 for 5 days was given during first and fifth weeks of radiation treatment, followed four to six weeks later by radical surgery. RESULTS: Among 108 patients there were 74 males and 34 females. Mean age was 54.4 years in male and 52.3 years in female. Mean follow up periods was 41.3 months. Complete follow up was in 96.4% of patients. Curative resection was done in 90 patients (83.3%). The most common type of surgery was low anterior resection in 40 (44.4%) and unresectable patients in 10 (9.3%). Postoperative morbidities were wound infection (n=10, 9.2%), anastomostic leakage (n=2, 1.9%), and anastomotic stricture (n=1, 0.9%). After chemoradiation, tumor stage were as follows: pathologic complete remission was in 7 (6.5%), pT1, T2 N0 (stage I) was in 21 (19.4%), T3N0 (stage II) was in 28 (25.9%) and T3 N (+) (stage III) was in 34 (31.5%). The rate of local recurrence was 10.7% in stage II and 20.6% in stage III. Systemic recurrence was 21.4% in stage II and 47.1% in stage III. 5 year survival rate according to T stage was T0 (100%), T1 (100%), T2 (79.5%), T3 (43.7%), T4 (33.3%) (p=0.0088). According to N stage, N (-)(72.0%) and N (+) (35.7%)(p=0.002). Among T3 patients, 5 year survival rate was N (-)(58.2%) vs. N (+)(32.0%)(P=0.0228). CONCLUSION: Preoperative chemoradiation followed by total mesorectal excision downstaged locally advanced rectal cancer and showed high resectability. Clinical outcomes correlated with pathologic T and N downstaging. Patients who did not show pathologic T and N downstaging showed high local and systemic failure and poor prognosis.