Rasburicase is a new treatment for hyperuricemia, a metabolic manifestation of tumor lysis syndrome (TLS). Rasburicase has a unique mechanism of action that allows uric acid byproducts to be easily excreted in the urine. Clinical trials have shown that rasburicase has a rapid onset of action that allows chemotherapy to be delivered on time and prevents hyperuricemia-related complications, including renal compromise. The drug has been used successfully in adults and children. The main side effect of rasburicase is the potential for a hypersen sitivity reaction. The drug is contraindicated in patients with glucose 6-phosphate dehydrogenase (G6PD) deficiency because this can precipitate hemolytic anemia. The drug has not been studied in patients with a history of allergies or asthma. Oncology nurses play a major role in the assessment and management of TLS-related complications. They must assess patients for G6PD deficiency and signs and symptoms of hypersensitivity reaction before and during chemotherapy or other therapeutic interventions. Nurses play a direct role in preventing complications related to TLS and contributing to the quality of life in this patient population.