Background/aim: Since the majority of the IgG4-related disease (IgG4-RD) patients in the literature are from the Far East and the United States, there is a lack of large series from other parts of the world. We aimed to identify the clinical characteristics and outcome of Turkish IgG4-RD patients from a tertiary center.Materials and methods: Fifty-two patients classified as having definite IgG4-RD according to comprehensive diagnostic criteria were included in the study. Patients not fulfilling the definite criteria due to lack of pathologic specimen and/or serum IgG4 levels were excluded (n = 47). Clinical, laboratory, and histopathological features and treatment approaches were analyzed.Results: Median age at diagnosis was 51.1 years and sex predominance was not observed (male/female: 26/26). Median follow-up duration was 18 (IQR 25-75: 8-35) months. Retroperitoneal fibrosis was the most frequent presentation. Twenty-four (46.1%) patients had localized involvement. Corticosteroids were the mainstay of treatment (92.5%). Rituximab had been used for cases resistant to previous treatment or with relapses in 19 (47.5%) patients. A complete response was achieved in 52.5% and partial response (