OBJECTIVE: A substantial portion of granulomatosis with polyangiitis (GPA) patients present with localized disease limited to the upper respiratory tract, however; disease spectrum and prognosis of these patients are unclear. The aim of this study is to describe the clinical characteristics and outcome of patients with localized GPA. METHODS: This was a retrospective descriptive case series of patients with a biopsy proven localized GPA presenting to a single tertiary rheumatology service between January 1995 and September 2015. RESULTS: A total of 5 patients, median age 56 years (range 48 to 59 years) at diagnosis and 80% female, were identified. The median follow-up period was 42 months (range 15 to 62 months). Diagnosis was delayed with median time to diagnosis of 12 months (range 3 to 36 months), and patients underwent 1-3 ear, nose, and throat surgeries during the period of diagnostic delay. Sinusitis was the most frequent symptom in all patients, followed by otomastoiditis with cranial nerve palsies (n=2) and orbital mass (n=1). Antineutrophil cytoplasmic antibody (ANCA) was positive initially in 2/5 patients (40%). Two patients with otomastoiditis and cranial nerve palsies progressed to systemic disease with ANCA positive conversion. These two cases along with a case with orbital mass were refractory to standard treatment of cyclophosphamide with glucocorticoids requiring rituximab treatment. CONCLUSION: Patients with localized GPA may progress to systemic disease over the disease course, and may have aggressive disease refractory to standard treatment. Close monitoring for systemic symptoms and repeated ANCA testing is required in patients with localized GPA.