Tests for renal function were performed in 75 smear positive children with acute malaria together with 10 control children. Plasmodium vivax and Plasmodium falciparum accounted for 52 and 46 per cent cases, respectively. Renal impairment in the form of decreased endogenous creatine clearance (less than 65 ml/min/m2) was noted in 36 of the 75 children with malaria. Plasmodium falciparum was responsible for 66 per cent and P. vivax accounted for 30 per cent cases of renal impairment. Plasmodium falciparum parasitaemia produced significantly greater reduction in endogenous creatine clearance (r = 0.198). Fourteen of 36 patients with decreased endogenous creatine clearance who attended for follow-up showed that their creatinine clearance had returned back to normal.