Small cell carcinoma of the esophagus (SmCCE) is a rare disease which is considered to be more malignant than the most common types of esophageal cancer. The optimal treatment strategy for this disease still remains controversial. A 69-year-old male was diagnosed to have SmCCE (stage IIIA, T3N1M0). Due to the patient's poor general condition, chemo-radiotherapy consisting of S-1/cisplatin therapy and a total of 60 Gy of radiotherapy was performed. After the treatment, the main lesion completely disappeared while some ulceration remained. A histological examination revealed no viable cancer cells in biopsy specimens obtained by endoscopy. Computed tomographic examinations showed a decreased wall thickness of the esophagus and an improvement in the swelling of the lymph nodes. S-1 monotherapy was administered following the main chemoradiation therapy, and it was performed for a total of 20 courses. The patient has been doing well without recurrence for over 3 years. We judged the effect to be a complete response. This combination chemo-radiotherapy with S-1 and cisplatin may therefore be one of the effective treatments against SmCCE.