OBJECTIVE A retrospective analysis was performed to investigate the treatment outcome and the significance of radiation therapy for esophageal cancer in patients over 80 years old. METHODS Between 1971 and 1990, 257 patients with squamous cell carcinoma of the esophagus were treated by radiation therapy. Of these, 40 patients over eighty years old were investigated. The reasons for radiation therapy were advanced age alone in 22 patients, Stage IV disease in 13, and medical problems in 5. Of these, 33 patients (83%) could be irradiated over 60 Gy. The cases with Stage I to III disease who received 60 Gy or more were defined as the curative radiation therapy group, and the others were defined as the palliative radiation therapy group. Actuarial survival rates were determined by the Kaplan-Meier method. RESULTS The 5-year disease-specific survival rate for the curative radiation therapy group (n = 25) was 34% with three intercurrent deaths. None of the patients in the palliative radiation therapy group (n = 15), including 13 cases with Stage IV and two given-up cases, survived over 2 years. No severe radiation damage was observed in either group. The 5-year disease-specific survival rate was 64% for complete response cases of local response, and 8% for partial response and no change cases (p < 0.01). The 5-year disease-specific survival rate was 64% for the patients with tumors less than 5 cm in length, and 8% for the patients with tumors over 5 cm in length (p < 0.001). No significant survival differences were found in regard to sex and tumor location. The patients with superficial spreading type and polypoid type tumors according to the radiologic findings had better prognoses than the patients with ulcerative type and circumferential type tumors. CONCLUSIONS Radiation therapy is a safe and effective treatment for esophageal cancer in patients over 80 years old.