Up to date, standard treatment of locally advanced rectal cancer is preoperative radiotherapy with concurrent chemotherapy. Results of FFCD and EORTC French randomised trials showed that preoperative radiochemotherapy with 5-fluorouracil (5FU) compared with radiotherapy increases operative specimen sterilisation and local control, without any benefit on overall survival. One of the greatest challenges in rectal cancer is to improve schedules of pre operative chemoradiotherapy. Oxaliplatin is proved to be a radiosentitizer and to be effective on advanced colorectal cancer. Consequently it is an adequate drug to associate with 5FU and radiation. Several phases I and II studied the association between 5FU infusion-oxaliplatin-radiation therapy or capecitabine-oxaliplatin-radiation therapy with a moderate toxicity (essentially diarrhoea) and a promising tumoral activity. All the studied schedules seem to have a similar efficiency with a questionable increased toxicity with continuous administration of 5FU or capecitabine. Only randomized trials comparing 5FU to 5FU or capecitabine plus oxaliplatin will attest the benefit of oxaliplatin on local control, sphincter preservation and overall survival, and will estimate its toxicity compared with monochemotherapy.