We evaluated the efficacy of chemoradiotherapy (CRT) for advanced esophageal cancer, from the view point of response. The relationship between chemo-radiosensitivity and dihydropyridine dehydrogenase (DPD), thymidylate synthase (TS), and p53 was investigated immunohistochemically. Thirteen patients with inoperable advanced esophageal cancer were involved in this study. CDDP of 10 mg/m2/day and 5-FU of 335 mg/m2/day were infused intravenously (day 1-5, day 15-19). Radiation was delivered concomitantly at a total dose of 30 Gy. Expressions of p53, DPD and TS were detected using immunohistology in the biopsy samples taken before CRT from 8 patients. Partial response was observed in 8 cases, no change in 4 cases, and progressive disease in one case. The overall response rate was 62%. The reduction rate was higher in tumors positive for p53 expression than in negative ones. The same was true for DPD and TS. The Treatment effect was more precisely predicted by combination of p53, DPD and TS. CRT with low-dose CDDP + 5-FU chemotherapy was effective and combination with p53, DPD, and TS might be a predictive marker for CRT in patients with advanced esophageal cancer.