Hydration, urinary alkalization, and allopurinol are the standard of care in the treatment and prevention of hyperuricemia. Rasburicase is a new alternative for the management of hyperuricemia in cancer patients. Criteria for the use of rasburicase were developed by the Hematology/Oncology Pharmacy and Therapeutics Subcommittee of the Detroit Medical Center and implemented in 2003. The guidelines limit rasburicase use to one dose, with additional doses as needed, compared to the five doses recommended by the manufacturer, in cancer patients with hyperuricemia and bulky tumor who require immediate chemotherapy. During the period of March to September 2003, eight patients received rasburicase, according to the guidelines, for the management of hyperuricemia. One dose of rasburicase produced a rapid and sustained therapeutic effect of lowering the plasma uric acid levels in all patients. The levels remained below 4 mg/dL throughout the administration of chemotherapy for up to 96 h. Utilizing the guidelines resulted in a significant cost savings of 100,000 US dollars.