To identify and characterize patients with orbital masses in a monocentric cohort of 1142 GPA patients followed up from 1990 until the end of 2010 with regard to disease stage, local orbital inflammation, course of disease and outcome and to assess the efficacy of immunosuppressive treatment. All GPA patients fulfilling ACR criteria or Chapel Hill Consensus Conference definitions or who had localized GPA and who developed orbital masses were evaluated regarding the course and outcome of the orbital masses (assessed by MRI, ophthalmologist and ENT specialist), all other clinical manifestations, disease stages, ANCA status, immunosuppression and its side effects and surgical procedures. Of 1142 GPA patients 58 developed orbital masses during a median follow-up of 101.5 months (range 23-255 months). Forty patients fulfilled the inclusion criteria and had complete clinical assessments 44% females, median age 43 (20-74) years, 85% ANCA positive. Seventy-five per cent (29/40) had systemic disease when orbital masses occurred; both orbits were affected in 30%. Seventy-two per cent had evidence of infiltration from paranasal sinuses. Under highly potent immunosuppression (mostly CYC and glucocorticoids), 41% were refractory, 24% had unchanged activity, 24% showed a response and 8.1% had complete remission. Forty-four per cent had relapses of orbital masses. Seventy-two per cent developed visual impairment, 19% suffered blindness. Blindness was associated with a longer time to remission and a relapsing and refractory course. Orbital masses are a rare manifestation of GPA and are characterized by a refractory course and by a high rate of local damage. Patients with a refractory or relapsing course are at higher risk of developing blindness.