The patient was a 69-year-old man who, during a routine health examination, was found to have irregular mucosa in the lower esophagus, which was subsequently diagnosed by endoscopy as Barrett's esophagus. Endoscopic ultrasonography led to the diagnosis of advanced esophageal cancer with a depth of invasion corresponding to T2. While surgery was indicated, it was not considered feasible because of pleural adhesions due to old tuberculosis. Therefore, chemotherapy with TS-1 at the dose of 80 mg/day (4-week therapy followed by a 2-week withdrawal period) and CDDP at the dose of 3 mg/day (4-week of 5-day therapy followed by a 2-day withdrawal period) was instituted, followed 3 weeks later by the addition of radiotherapy with 1.8 Gy/day (5 times/week). Follow-up endoscopy revealed evident reduction in the lesion size 73 days after the start of TS-1 therapy, and complete disappearance of the lesion 185 days after the start of therapy. Grade 1 leukopenia was the only adverse effect of TS-1 noted in the patient. Treatment of Barrett's esophageal cancer is often conducted in accordance with the principles of treatment of esophageal squamous cell carcinoma, and surgical resection represents the most effective treatment. On the other hand, there have been no reports of effective adjuvant therapy. Based on our experience, the therapeutic strategy employed in this patient is considered to offer promise for the treatment of Barrett's esophageal cancer.