Pulmonary-renal syndrome with "triad" involvement due to small vessel vasculitis. We describe the clinical course and morphologic findings of a 22-year-old woman presenting with a systemic disease that included nasal ulceration, hemoptysis and rapidly progressive renal failure. Biopsies of nasal septum and lung revealed small vessel leukocytoclastic angiitis while renal biopsy showed a diffuse crescentic glomerulonephritis. Immunosuppressive therapy resulted in remission of clinical symptoms and resolution of glomerulonephritis as documented in a followup biopsy. Although her clinical presentation with triad organ involvement strongly suggested Wegener's granulomatosis, this case illustrates that other varieties of vasculitis may mimic Wegener's granulomatosis. 