With the introduction of total mesorectal excision in rectal cancer treatment, local recurrence rates could be reduced below 10%. Previously such results could be achieved only in combination with multimodal therapy. Therefore the role of multimodal therapy had to be redefined. Randomized controlled trials have shown that the local recurrence rate can be reduced with no effect on overall survival and that neoadjuvant radiotherapy is superior to adjuvant radiotherapy. Controversy exists however about the best way of application, as either short-course radiotherapy (5x5 Gy) or combined radiochemotherapy, but not about its necessity, especially considering recent reports about late side effects of radiotherapy. It was the aim of this paper to explore the literature for the amount of radiotherapy surgical patients for rectal cancer really need. Interestingly, those with high rectal tumors do not benefit from radiotherapy. Further randomized trials are however required to address the need of radiotherapy in UICC tumor stages II or III with negative circumferential margin.