Orbital manifestation of Wegener's granulomatosis is diverse and diagnosis is often difficult. This study aims to improve the diagnostic strategy in orbital Wegener. A review of the diagnostic process in patients in whom a diagnosis of orbital WG was considered. Thirty-three patients were analysed, consisting of 15 patients with orbital WG, 11 with idiopathic orbital inflammation, 6 with orbital sarcoidosis and one with aspergillosis. Diagnostic findings indicating orbital WG were ear/nose/throat involvement, multiple organ system involvement, a positive ANCA, and on histology vasculitis, whereas granulomatous inflammation without signs of vasculitis was more indicative of another orbital disease. The diagnostic process of orbital WG should include CT scanning of the orbit and sinuses, ANCA blood testing, consultation of a rheumatologist, an ophthalmologist, and an ear-nose-throat specialist, and biopsy of an easily accessible, active inflammatory lesio