We describe a 68-year-old postmenopausal woman who presented with a history of rapidly enlarging lumps in both breasts. Though the breast lumps appeared suspicious on ultrasonography, the core biopsy was reported to be benign. In view of the clinical and radiological suspicion of malignancy, she underwent a diagnostic excision of both the lumps, the histopathology was consistent with mammary hibernoma. To the best of the authors’ knowledge, this is the first report of a bilateral mammary hibernoma in an elderly postmenopausal woman. Given the clinical presentation, it is important to differentiate mammary hibernoma from carcinoma breast, which is a more common condition in this age group. However, preoperative diagnosis is challenging in view of the lack of definitive radiological and histological features. Although benign, hibernoma may have a propensity for local recurrence and, therefore, complete surgical excision remains the mainstay of treatment.