The clinical course and outcome of rapidly progressive glomerulonephritis (RPGN) of variable etiology are not well defined in children. The present investigation reports on the clinical characteristics, the course and outcome, as well as the results of treatment of 13 children with apparent postinfectious RPGN. Three of 7 patients with documented streptococcal RPGN and 3 of 6 patients with RPGN of nonstreptococcal etiology progressed to chronic renal failure. In some patients, anticoagulant and antiplatelet therapy appear to have improved survival. The severity of crescent formation, not the presumable etiology, appears to be a reliable prognosticator.