The overall incidence of tumor lysis syndrome in adults is not well defined, and its occurrence can be unpredictable. Several strategies are available for the prevention and treatment of tumor lysis syndrome, with rasburicase being the most recent. Rasburicase is a recombinant urate oxidase enzyme approved for use by the Food and Drug Administration in patients who are at risk of developing tumor lysis syndrome or for the management of elevated uric acid levels. Clinical trials have demonstrated rasburicase to be effective in both the pediatric and adult populations, although the drug is currently indicated only for use in the pediatric population. Adverse effects associated with rasburicase can be significant, ranging from anaphylactic reactions to methemoglobinemia. To ensure accuracy of uric acid test results, special laboratory handling procedures must be followed while patients receive rasburicase. Compared with allopurinol and intravenous sodium bicarbonate, rasburicase is costly, and therefore judicious use of the medication is warranted.