From 1988 to 1990, 53 patients with squamous cell carcinoma of the thoracic oesophagus underwent subtotal oesophagectomy after either preoperative hyperthermo-chemoradiotherapy (HCR therapy) or chemoradiotherapy without hyperthermia (CR therapy), in a prospective randomized trial carried out to examine the effects of hyperthermia given preoperatively. The two groups (27 patients given HCR therapy and 26 given CR therapy) were found to be comparable with regard to prognostic factors of age, site of carcinoma, TNM stage, etc. Following preoperative evaluation by an upper GI series and endoscopy, a subtotal oesophagectomy was done for all 53 patients. All the resected specimens, including the lymph nodes, were histopathologically examined, and the effects of preoperative treatment were evaluated by findings in the upper GI series and endoscopy, as well as based on the histopathology of the excised tissues. There were no viable cancer cells in the resected specimens of seven patients in the HCR therapy group (26.9%) and of two patients in the CR therapy group (7.7%). In addition, no hyperthermia complications were observed. The study suggests that preoperative HCR therapy may be a more beneficial therapy than preoperative CR therapy in patients with squamous cell carcinoma of the oesophagus who undergo a subtotal oesophagectomy.