Abstract The histologic diagnosis of Wegener's granulomatosis is usually challenging. It is made more so by the failure of most pathologists to realize that the disease is fundamentally neither a vasculitis nor a granulomatous reaction. This problem can contribute to delays in diagnosis and consequent adverse effects for patient prognosis. This article attempts to better describe the essence of Wegener's granulomatosis with the aim of enhancing diagnosis earlier in the course of the disease. Ann Diagn Pathol 6:329-333, 2002.