In locally advanced rectal cancer (uT3/uT4) resectability as well as local control is reduced. In the patients combined preoperative radiochemotherapy demonstrated an increase of resectability and a reduction of local recurrence. Radiotherapy was applied in standard blocks, 5 x 1.8 Gy up to 45 Gy. Chemotherapy consisted out of two cycles of 5-Fluorouracil (300-350 mg/m2/d) and Leucovorin (50 mg). Prior to radiotherapy additionally thermotherapy was carried out using the SIGMA 60 applicator BSD 2000 once a week. The hyperthermia method is based on heating up affected tissue compartments to temperature above 42 degrees Celsius without damaging surrounding tissue compartments. In regional hyperthermia tumors in the abdominal region are treated by emitting radio waves into the patient. 4-6 weeks after radiochemotherapy, surgery was performed. The therapeutic toxicity was acceptable and the resectability rate was up to 90%. Response rate to treatment was 60%. Our data with preoperative combined treatment in locally advanced rectal cancer revealed encouraging downstaging, local control, and survival rates.