[Objective] To explore the clinical features of IgG4-related urinary diseases so as to provide reference for the diagnosis and treatment of such diseases. [Methods] The clinical data of 4 cases of IgG4-related urinary system diseases diagnosed and treated in Xijing Hospital of Air Force Medical University during Aug.2019 and Dec.2023 were retrospectively collected.Here, we report on the diagnosis and treatment of these patients, analysing their symptoms, serology, imaging and pathology as well as their treatment and outcomes. [Results] The patients included 2 male and 2 female.The lesions were involved with the retroperitoneum and urinary system.Three patients had symptoms of lumbar pain.The imaging manifestations were complex, including retroperitoneal mass involving urinary system organs in 2 cases, tabdense shadow of the right kidney in 1 case, and simple cystic mass of kidney in 1 case.Serum IgG4 value was not detected before surgery.All patients underwent radical surgical treatment.Postoperative pathology showed fibrous tissue hyperplasia with a large number of plasma cells, lymphocytes, a few neutrophil infiltrates, and lymphoid follicles and obliterated vasculitis in some specimens.The number of IgG4⁺ plasma cells was more than 10 in all tissues under high power microscope.After surgery, 3 patients had symptoms improved, and serum IgG4 value was within the normal range; 1 patient (patem 3) had elevated IgG4 value during follow-up, received subsequent hormone therapy, and the serum IgG 4 level remained stable. [Conclusion] The symptoms of IgG4-related diseases involving the urinary system are non-specific, and the imaging findings are various, easily confused with other diseases.Early detection of serum IgG4 and biopsy pathology can help clinicians make correct diagnosis in the early stage.