From 1992 through 2001, 29 patients with stage I esophageal cancer were treated with radiation therapy. All patients had squamous cell carcinoma. Seventeen patients were treated with radiotherapy alone, and 12 were treated with a combination of chemotherapy and radiotherapy. Most of the chemotherapy regimens included cisplatin and/or 5-fluorouracil (5-FU). Twelve patients were treated with intracavitary irradiation (low-dose rate: 6, high-dose rate: 6) after external radiotherapy. Median fraction and total doses of external radiotherapy given were 2.0 Gy and 60.6 Gy, respectively. Median doses of intracavitary irradiation were 18 Gy/6 fractions in low-dose-rate brachytherapy and 13.5 Gy/4.5 fractions in high-dose-rate brachytherapy. The 5-year overall survival rate was 62%. The 5-year local control rate was 44%. Of the 29 patients, 9 had in-field recurrence in the esophagus and 1 had recurrence in the esophagus outside of the irradiated field. Of 9 patients with in-field local recurrence, 1 also developed mediastinal lymph node metastases and 1 had distant metastasis. Radiation therapy is an effective treatment modality for stage I esophageal cancer.