Between 1962 and 1970, 36 children with acute biopsy-proven poststreptococcal glomerulonephritis (PSGN) entered a prospective long-term follow-up study. The initial biopsies were scored into four histological grades using criteria based on endocapillary proliferation, leucocyte infiltration, epithelial hump and crescent formation; 5 patients had grade-1 (least severe), 14 grade-2, 15 grade-3 and 2 grade-4 biopsies. Two children died from rapidly progressive glomerulonephritis; both had grade-4 biopsies. Early repeat biopsy in 12 patients showed improvement in all but one patient who progressed from grade 2 to type 2 mesangiocapillary glomerulonephritis (MCGN). The initial biopsy grade correlated significantly with heavy proteinuria (² = 9.73,P<0.01) but="" not="" with="" hypertension,="" haematuria="" or="" renal="" functional="" impairment.="" follow-up="" observations="" were="" made="" after="" mean="" periods="" of="" 9.5="" years="" (range="" 5.4–12.4="" years;="" 32="" subjects)="" and="" 19.0="" years="" (range="" 14.6–22="" years;="" 30="" subjects).="" none="" of="" the="" survivors="" had="" an="" abnormal="" plasma="" creatinine.="" only="" one="" patient="" (grade-3="" biopsy),="" a="" female="" with="" a="" subsequent="" history="" of="" recurrent="" pyelonephritis,="" was="" hypertensive.="" isolated="" microscopic="" haematuria="" persisted="" in="" 1="" grade-2="" and="" 2="" grade-3="" subjects.="" one="" grade-2="" subject="" had="" proteinuria="" secondary="" to="" mcgn="" and="" one="" grade-3="" subject="" had="" mild="" proteinuria="" and="" borderline="" hypertension.="" although="" 20%="" of="" subjects="" had="" urinary="" abnormalities,="" we="" conclude="" that="" the="" long-term="" outcome="" of="" psgn="" in="" children="" is="">