Purpose: The aim of this study was to investigate efficacy and toxicity of a modified 5-fluorouracil (5-FU),folinic acid, oxaliplatin (mFOLFOX-4) regimen followed by infusional 5-FU concomitant with radiotherapy forcuratively resected stage III rectum adenocarcinoma patients. Patients and Methods: Between April 2005 andJuly 2009, 55 operated stage III rectum cancer patients were evaluated retrospectively. mFOLFOX-4 regimen(oxaliplatin 85 mg/m2 1st day, folinic acid 200 mg/m2 1st day, 5-FU 400 mg/m2 iv bolus 1st day, 5-FU 1600mg/m2 46 hours continuous infusion) was applied every 2 weeks. After four courses of mFOLFOX-4, 50.4 Gy(1.8 Gy in 28 fractions) radiotherapy with continuous 5-FU 200 mg/m²/day by infusion pump were given. Oncompletion of chemoradiation four more mFOLFOX-4 courses were given. Results: Median age of the patientswas 54 years (range 23-73 years). Low anterior resection was performed in 37 (67.3%) and abdominoperinealresection in 16 (29.1%) . Ten (18.2%) patients were at stage IIIA, 24 (43.6%) at stage IIIB and 21 (38.2%) atstage IIIC. Planned chemotherapy cycles were completed in 92.7% of patients. Grades 3-4 toxicity includedneutropenia (9.1%), febrile neutropenia (3.6%), anemia (3.6%), diarrhea (21.8%), neuropathy (9.1%), renaltoxicity (3.6%), hepatotoxicity (5.5%). Median follow-up time was 30 (9-57) months. Local recurrence anddistant metastasis was observed in 3 (5.5%) and 10 (18.2%) patients, respectively. Ten (18.2%) patients diedduring follow-up. Three years disease free survival and overall survival were 67.5% and 77.3%, respectively. Conclusion: mFOLFOX-4 following chemoradiotherapy with continuous 5- FU infusion is an effective and welltolerated adjuvant treatment for stage III rectal carcinoma patients.