The use of combined modality regimens has been well established in the treatment of stages II and III rectal cancer. The most common chemotherapy regimens used include continuous-infusion 5-FU delivered with the help of a central venous catheter and the use of portable pumps. These regimens are expensive and can potentially develop line problems. The availability of the oral agent UFT in combination with oral leucovorin prompted the development of an all-oral chemotherapy regimen that could be combined with radiotherapy. At The University of Texas M. D. Anderson Cancer Center, we routinely use combined chemotherapy and radiotherapy preoperatively for the treatment of rectal cancers, and decided to conduct a phase I trial in which UFT and leucovorin was used instead of the conventional 5-FU. The preliminary results are encouraging and seem to demonstrate the feasibility of this approach.