Seventy-two patients with severe falciparum malaria are described. Twenty-four (33.3%) were complicated by acute renal failure. Comparing patients with renal failure and those without, statistically significant differences occurred regarding presence of cerebral malaria (83% vs 46%), jaundice (92% vs 33%), and death (54% vs 17%). A significantly higher number of patients with renal failure were nonimmune visitors to malaria endemic regions. Renal failure was oliguric in 45% of cases. Dialysis was indicated in 38%, 29% died in early renal failure, and 33% recovered spontaneously. It is concluded that falciparum malaria is frequently complicated by cerebral malaria and renal failure. As nonimmune individuals are prone to develop serious complications, malaria prophylaxis and vigorous treatment of cases is mandatory.