Two children with a syndrome of pulmonary hemorrhage and necrotizing, nonimmune glomerulonephritis are reported. A boy and girl, both of East Indian descent, developed recurrent lung infiltrates from the age of 3 months and 2 years, respectively. Both subsequently presented with pulmonary hemorrhage, fever, arthritis, hematuria, and nephrotic range proteinuria at 1.5 and 6 years of age, respectively. Renal biopsy in each case showed acute, severe, focal and segmental, necrotizing and crescentic glomerulonephritis without immune deposits. Subsequent renal biopsies revealed severe glomerular and tubulointerstitial scarring. No vasculitis or granulomas were seen on renal, skin, or lung biopsies. Antineutrophil cytoplasmic antibodies (ANCA) were not detected in sera taken 1.5 years in the boy and 3.5 years in the girl after the onset of renal disease. The boy was treated with prednisone, azathioprine, and plasmapheresis, but developed progressive renal impairment and commenced dialysis within 4 years. Subsequent to renal transplantation, he developed an immunoblastic lymphoma and died. The girl was treated initially with prednisone and later with cyclophosphamide. After 4 years, she had a normal glomerular filtration rate (GFR). While necrotizing nonimmune glomerulonephritis associated with pulmonary hemorrhage is rare, and cases are characteristically difficult to classify because of many overlapping features, it is possible that these children had a unique illness.