The current standard of care for patients with stage T3 rectal cancer is adjuvant combined-modality treatment with radiation and fluorouracil (5-FU)-based chemotherapy. Although data from randomized phase III trials comparing preoperative and postoperative combined-modality therapy are lacking, preoperative therapy is an option in T3 disease and can be considered the standard of care for T4 disease. Given its effects in reducing systemic disease in stage IV rectal cancer and its potential for radiosensitization of target tumors, oxaliplatin (Eloxatin), a new cytotoxic agent from the diaminocyclohexane platinum family, is being evaluated in preoperative combined-modality regimens in a Cancer and Leukemia Group B (CALGB) phase I/II study (protocol 89901) in T4 disease and an Eastern Cooperative Group (ECOG) phase I study (E-1297) in locally advanced T3 or T4 disease.