Background: Idiopathic granulomatous mastitis (IGM) is an uncommon chronic inflammatory disease of the breast with uncertain optimal treatment regimen. In this study, our purpose was to report our clinical experience with 74 IGM patients who were treated wide local excision with or without steroid therapy. Patients and Method: 74 cases diagnosed histologically as IGM were identified from surgical and pathological records between January 1995 and January 2012. Group 1 (surgery-only group) comprised 53 patients, and the 21 patients in group 2 were treated with corticosteroids prior to surgical treatment (steroid-and-surgery group). Results: Follow-up data were complete for 67 (91.7%) of the 73 patients. Recurrence developed in 4 (7.5%) patients in the surgery-only group, while there was no recurrence in the steroid-and-surgery group; the difference was not statistically significant (p = 0.19). Conclusion: Systemic steroid therapy with surgical resection is the recommended first-line treatment strategy for IGM.