Postinfectious glomerulonephritis (PIGN) is by far the most common cause of acute glomerulonephritis (AGN) in children. Numerous infectious agents, including bacteria, viruses, fungi, and parasites, have been implicated in PIGN. However, nephritogenic strains of group A betahemolytic streptococci are the most frequent culprits. Clinical manifestations of this syndrome, including hematuria, proteinuria, oliguria, fluid overload, and azotemia, are the result of proliferative and inflammatory changes of the renal glomeruli secondary to immunologic injury.