Small cell carcinoma of the esophagus is rare, with a poor prognosis, and there is currently no standard therapy. Here we report a case of small cell carcinoma of the esophagus with right supraclavicular lymph node metastasis which was successfully treated by chemoradiotherapy. A 55-year-old man was admitted to our hospital with a right-sided neck tumor. The neck tumor was diagnosed as a small cell carcinoma by aspiration cytology. Endoscopy revealed an irregular tumor in the middle thoracic esophagus, 31 cm from the upper incisor teeth, but malignant cells were not detected from an esophageal biopsy. Right supraclavicular lymph node metastasis was detected by computed tomography and positron emission tomography computed tomography, and aspiration cytology revealed small cell undifferentiated carcinoma cells. The patient was diagnosed with a small cell carcinoma of the esophagus with supraclavicular lymph node metastasis, stage III: T2N3M0. Concurrent chemoradiotherapy using 5-fluorouracil and cisplatin was started. Lymph node reduction occurred from day 3, and endoscopy two months after chemoradiotherapy showed only a scar. We diagnosed the patient in complete remission, and he continues to do well with a recurrence-free status of 14 months after initial chemoradiotherapy.