To gain maximal effectiveness while decreasing toxicity by giving 5-fluorouracil for 45 minutes starting just within 5 minutes after the completion of radiotherapy thrice weekly.Thirty-eight patients with locally advanced rectal cancer were enrolled in the study. Ranges of total radiation doses were between 50.4 Gy and 61.2 Gy with a median of 59.4 Gy with fraction size of 1.8 Gy five times weekly. 5-fluorouracil was administered thrice weekly with the dose of 250-300mg/m2/day concomitantly with radiation therapy.Median follow-up time was 30 months. Administration of chemotherapy concomitant with radiotherapy (p=0.089), AJCC stage III (p=0.079), Duke's stage C (p=0.079), presence of lymph node involvement (p=0.079) and presence of local recurrence (p=0.066) appeared to be effecting distant metastasis although differences did not reach statistically significance. Mean overall survival was 46 months in patients without any distant metastasis (SD: 3.28; 95% CI: 39.46 and 52.31) while it was 35 months in patients with distant metastasis (SD: 5.71; 95% CI: 23.52 and 45.90, p=0.016).Our results have provided further evidence of the ability of postoperative chemoradiotherapy to delay and prevent local recurrence and metastasis of rectal cancer.