From January 1988 to June 1992, 66 patients with resectable squamous cell carcinoma of the thoracic esophagus underwent preoperative adjuvant therapy. These patients were prospectively divided into two treatment groups; 32 were treated with radiofrequency wave local hyperthermia combined with chemoradiotherapy (hyperthermochemoradiotherapy; HCR), while the remaining 34 patients were treated with chemoradiotherapy alone (CR). There were no procedural complications in either group and the postoperative mortality was zero. In the HCR group, no viable cancer cells were found within the entire 5 mm-width slices of the resected specimen in eight patients (25%), while only two (5.9%) in the CR group (P < 0.05) demonstrate no viable cancer cells. The cumulative 3-year survival rate was 50.4% in the HCR group and 24.2% in the CR group. The present prospective trial demonstrated that the addition of hyperthermia to chemoradiotherapy resulted in a better local control and an improved long-term survival when treating patients with advanced esophageal carcinoma.