ObjectiveTo summarize the clinical characteristics of idiopathic granulomatous mastitis (IGM) and its experiences of diagnosis and treatment. MethodThe clinical data of 33 patients with IGM from January 2005 to December 2014 were analyzed retrospectively. ResultsThe mean age of the patients was 33 years. The pathological examination showed that 28 patients (85%) were typical granuloma, and 5 patients (15%) were immature granuloma, whom were confirmed after exclusion of other pathogens. Twenty-nine patients were received drugs treatment, among which 21 patients were cured by taking prednisone orally, 6 patients were cured by the combination of prednisone and methotrexate, 2 patients failed to be cured, and 13 patients relapsed after stopping taking medicine. Four patients with abscess ulceration were received surgical treatment, and 2 patients relapsed after the surgery. Fifteen recurrent patients all were took prednisone and methotrexate orally, among which 1 patient stopped taking medicine because of liver function damage, 1 patient was not fully relieved, and other 13 patients were cured again. ConclusionsThe clinical manifestations of IGM have no specificities. The diagnosis mainly relies on pathological examination. In the early phase of this disease, the treatment method of steroid or combined immunosuppressant has good effects. In case of ulceration and protracted course, surgical treatment should be considered as early as possible.