Between December 1980 and November 1984, the acute episode was studied prospectively in 187 children under 14 years presenting with acute poststreptococcal glomerulonephritis. The mean annual incidence was 19.5/10(5) children. The disease was mainly pharyngitis-associated and occurred throughout the year but peaked in the winter. The mean age was 5.4 years, and 71 percent of children were under the age of 8 years. Gross hematuria was the presenting feature in 93.6% of cases and was usually associated with edema. Hypertension was present in 45 percent, circulatory congestion in 27 percent, and heavy proteinuria in 22 percent of cases. The C3 level was low in 97 percent of the patients tested and returned to normal within 6-8 weeks. There were no deaths. Only one patient needed peritoneal dialysis. All except one patient were asymptomatic with normal creatinine within 8 weeks. The authors adopted a very optimistic attitude in the counseling of children with the disease and of their families.