Based on a 10-year experience with 50 patients who had Wegener's granulomatosis, a new classification is proposed based on anatomic site of involvement: upper airway or ear, nose, and throat (designated E), lung (L), and kidney (K). All combinations of ELK were seen. The system is offered as a unifying concept to embrace the terms midline granuloma, generalized or classic Wegener's granulomatosis, and limited Wegener's granulomatosis. Fourteen patients have died despite the use of corticosteroids and immunosuppressant therapy. Thirteen patients with renal involvement have survived for periods as long as 114 months; all were taking immunosuppressive agents.