Multimodal therapy for rectal carcinoma is--in contrast to colon cancer--largely based on adjuvant or neoadjuvant radiotherapy. Although radiotherapy reduces local recurrence rates, overall survival is hardly improved, while on the other hand specific complications of radiotherapy are recognized. Extended neoadjuvant treatment concepts including chemotherapy may improve long-term outcome, but to date this has not been demonstrated conclusively by randomized trials. New developments include intraoperative radiotherapy and the combination of hyperthermia with radiochemotherapy. Initial results from randomized studies are promising, but require confirmation by larger trials. At the same time the importance of optimal surgical treatment has been recognized as a prerequisite for favourable long-term results. Since this aspect has not received due attention in past protocols the optimal combination of surgery with other modalities and their time sequence cannot be determined presently.