Seventy-nine children with haemolytic uraemic syndrome (mean age 28 months) were randomly assigned either to a group receiving plasma infusions (plasma group,n=39) or to a group treated conservatively (control group,n=40). The duration of haemolysis, thrombocytopenia and anuria was similar in the two groups. Serum creatinine levels were similar in the two groups at the 1-month follow-up but were higher in the control group at 3 months (plasma group 49±14, control group 66±28 mol/l;P<0.02) and="" at="" 6="" months="" (plasma="" group="" 48±13,="" control="" group="" 63±21="">mol/l;P<0.005). the="" prevalence="" of="" proteinuria="" was="" also="" higher="" in="" the="" control="" group="" at="" the="" 6-month="" follow-up="" (plasma="" group="" 17%,="" control="" group="">P<0.02). however="" differences="" were="" no="" longer="" significant="" after="" 1="" year.="" renal="" tissue="" was="" examined="" in="" 54="" cases="" (plasma="">n=27; control group,n=27). Diffuse cortical necrosis was present in 7 cases in the control group but was absent in the plasma group (P<0.02). taking="" into="" consideration="" the="" higher="" serum="" creatinine="" levels,="" the="" higher="" prevalence="" of="" proteinuria="" during="" the="" first="" 6="" months="" of="" follow-up="" in="" the="" control="" group="" and="" the="" presence="" of="" diffuse="" cortical="" necrosis="" in="" this="" group="" compared="" with="" the="" plasma="" group,="" we="" conclude="" that="" plasma="" infusions="" should="" be="" regarded="" as="" beneficial.="" further="" study="" is="" needed="" to="" determine="" which="" plasma="" fraction="" is="">