The pathophysiology of hypoglycaemia in children with acute falciparum malaria, a frequent and serious complication, is unknown due to absence of data on glucose kinetics. We investigated the correlation between basal glucose production and plasma glucose concentration in 20 children (8 girls) with acute, uncomplicated falciparum malaria by infusion of [6,6-2H2]glucose. Median plasma glucose concentration was 4.5 (range 2.1-6.5) mmol/L and the median glucose production 5.0 (range 4.1-8.4) mg/kg/min. There was a positive correlation between basal glucose production and plasma glucose concentration (r = 0.53, P = 0.016). There was no correlation between the rate of glucose production and the plasma concentrations of alanine, lactate, counter-regulatory hormones or cytokines. It was concluded that, in children with acute uncomplicated falciparum malaria, endogenous glucose production is an important determinant of plasma glucose concentration, contrary to previous findings in adults with malaria, in whom peripheral uptake seems to be more important than glucose production in determining plasma glucose concentration.