OBJECTIVE The aim of this study is to evaluate long-term results of preoperative hyperthermia combined with chemotherapy and irradiation (HCR therapy) in patients with carcinoma of the rectum. METHODS Postoperative prognoses were compared among 36 patients with carcinoma of the rectum, who were given preoperative HCR therapy followed by surgery, and 52 patients undergoing surgery alone without any preoperative therapy. RESULTS There were significant differences in the prognosis between patients given preoperative HCR therapy plus surgery and those having surgery alone, and five-year survival rates were 91.3 and 64 percent, respectively. Particularly, for patients with tumors invading beyond the muscularis propria and/or with positive lymph node metastasis, a significantly longer survival was obtained with HCR plus surgery than in surgery alone (86.5 vs. 50.9 percent and 92.9 vs. 51.7 percent, respectively). However, no significant differences were observed in the postoperative prognosis for cases with no lymph node metastasis and/or with tumors limited to the muscularis propria between these two groups. CONCLUSIONS These data clearly demonstrated the effectiveness of preoperative HCR therapy for improving long-term results of patients with carcinoma of the rectum, especially those demonstrating an advanced stage of disease.