Forty-three children with crescentic glomerulonephritis (GN), having large crescents in more than 50% of the glomeruli, were observed during a period of 22 years. There were 17 boys and 26 girls between the ages of 3.5 and 14 years (mean 8.7 +/- 2.6). Thirty-one patients (72%) presented with acute nephritic features and increasing renal insufficiency (rapidly progressive GN) whereas 12 had an insidious onset with nephrotic syndrome, or rarely with nonspecific symptoms. Eleven patients had evidence of poststreptococcal GN and 6 an underlying systemic disorder. Renal biopsy showed large crescents in greater than 80% of the glomeruli in 38 cases (100% in 28) which were predominantly fibrocellular or fibrous in 80% of the patients. Nineteen patients (44%) were treated with prednisolone, cyclophosphamide and dipyridamole; in addition, 8 were also given anticoagulants. Six patients received pulse doses of corticosteroids. In 23 patients, there was inexorable progression of renal failure, 14 showed partial improvement but subsequently had varying degrees of renal insufficiency and in 6, there was recovery of renal function with normal levels of serum creatinine. Of the latter, 4 had received immunosuppressive anticoagulant therapy and 2 only supportive care. Of 11 patients with poststreptococcal crescentic GN, 7 progressed to end-stage renal disease and 2 developed chronic renal insufficiency. Our findings confirm the poor outcome of crescentic GN in children, irrespective of the underlying etiology. In a small proportion of cases, the disorder may have an insidious onset and a slowly progressive course, but an equally grave prognosis.