Rasburicase (Fasurtec, Elitek, Sanofi-Synthelabo) is a new recombinant urate oxidase developed for the prevention and treatment of hyperuricaemia. It has a half-life of 17-21 h and produces rapid (within 4 h) and pronounced reductions in plasma uric acid concentrations. To date, rasburicase has been tested in four clinical trials conducted in patients with cancer (primarily haematological malignancies). It successfully alleviated hyperuricaemia in 98% of patients and prevented this complication in 99.6% of those who were at risk. In a stratified, randomised trial, rasburicase was more effective than allopurinol. Most patients had improved or stabilised renal function during rasburicase treatment, despite ongoing chemotherapy-induced tumour lysis. Except for occasional instances of haemolytic anaemia and methemoglobinaemia in patients with glucose-6-phosphate dehydrogenase deficiency, rasburicase was well-tolerated, with a low frequency of mild adverse events. Rasburicase is a safe and effective agent in the prevention or treatment of hyperuricaemia in cancer patients.