Hyperthermia combined with irradiation and chemotherapy was prescribed for patients with resectable or unresectable squamous cell carcinoma of the esophagus. The long term results were compared between two groups of patients; one group was treated with chemotherapy, radiotherapy and hyperthermia (HCR), and the other was treated with chemotherapy and radiotherapy, but not hyperthermia (CR). The five year survival rates of patients with resectable carcinoma, given preoperative HCR or CR, were 43.2 and 14.7 per cent, respectively; the difference was statistically significant (p less than 0.05). The two year survival rates of those with unresectable carcinoma and receiving HCR or CR were 15.5 and 1.2 per cent, respectively. In particular, for the patients classified as TNM Stages I and II, a significantly longer survival period was obtained with HCR. As severe side effects in patients given hyperthermia were nil, this treatment deserves serious consideration when treating patients with a malignant lesion of the esophagus.