From March 1992 to October 1997, a total of 38 patients with histologically proven esophageal cancer received combination therapy of daily low-dose cisplatin (CDDP) and radiation therapy. The clinical stages (UICC 1997) were I in 3, IIA,B in 13, III in 13, and IVA in 9 patients. CDDP (5 mg/m2) was administered intravenously with 100 ml saline 30 min before each irradiation from Monday to Friday. All patients received at least 60 Gy of radiation therapy. The average number of CDDP administrations was 23, and the mean total CDDP dose was 115 mg/m2. Of the 38 patients, 14 patients completed full course of chemoradiation therapy. The overall survival rates at 1, 2, and 5 years were 51%, 19%, and 8%, respectively. The median survival period was 12 months. The objective response rate was 82% with 11 (29%) CR. Survival of the stage II-IVA patients who received daily low-dose CDDP and radiation therapy was a little better than that of historical control patients who were treated by radiation therapy alone. Most of the patients experienced nausea. Grade 3 esophagitis was observed in two (5%) patients. Grade 4 leukocytopenia and thorobocytopenia were observed in one (3%) and two (5%) of the patients, respectively. Except for leukocytopenia (18%), frequencies of toxicity of grade 3 or more were less than 10%. Although the results indicate that daily low-dose CDDP combined with radiation therapy may slightly improve the survival of esophageal cancer patients with acceptable toxicity, further efforts should be made to optimize clinical trial protocols. Escalation of daily CDDP dose should be considered to obtain a more effective radiosensitizing effect.