Glomerulonephritis is a very unusual feature of relapsing polychondritis. A 16-year-old woman presented with microscopic hematuria and severe renal insufficiency during the course of relapsing polychondritis. A renal biopsy specimen disclosed focal segmental proliferative glomerulonephritis with necrotizing lesions and crescent formation. Immunofluorescent studies suggested immune complex mediated glomerular injury. The renal involvement appeared during high-dose steroid therapy. Subsequently, she was treated by adding plasmapheresis and cyclophosphamide during 6 weeks, with sustained improvement. A regimen of plasmapheresis and immunosuppression warrants consideration for use in cases of relapsing polychondritis with glomerulonephritis.