The use of concomitant continuous infusion chemotherapy and radiation therapy in the treatment of a variety of tumors has produced, in relatively limited clinical experience, substantial improvements in complete response and survival rates. Although there is still a need to establish the most effective combinations, concentrations, and scheduling of drugs, as well as optimum dose and fractionation of radiation, a number of benefits have already been recorded with this approach. Organ preservation is maximized in all but the most advanced cancers of the anus, esophagus, and bladder. In advanced head and neck cancers, particularly in the paranasal sinuses when bone destruction and infiltration have occurred, the total dose required for effective therapy can be reduced by 15%-30%, which substantially lowers the rate of complications. Therapeutic gains have also been seen in the treatment of other primary and recurrent gastrointestinal and gynecologic malignancies and their hepatic metastases. Finally, there is considerable potential for this approach in the treatment of bulky or recurrent soft-tissue sarcomas, particularly in the extremities.