In Gambian children with Plasmodium falciparum infection, uncomplicated malaria fever is associated with moderately elevated circulating tumour necrosis factor (TNF) levels. We review clinical and in vitro data suggesting that schizont rupture stimulates bursts of TNF production that mediate paroxysms of malaria fever, and that the fever could possibly be beneficial to the host. Mean plasma TNF levels are ten times higher in fatal cerebral malaria than in uncomplicated malaria, providing support for the hypothesis that excessive TNF production may contribute to the pathology of severe infection.