Synchronous bilateral Paget’s disease of the nipple is extremely rare. In the present study, we report a case of synchronous bilateral Paget’s disease in a 45-year-old woman who had a medical history of gastric cancer. The patient presented with a 6-month history of eczema and itching in both nipples. Mammography and ultrasonography did not reveal any mass lesions in the bilateral breast, and computed tomography and bone scintigraphy showed no site of distant metastasis. The patient was scheduled for mastectomy and sentinel node biopsy. The histological diagnosis was Paget’s disease of the breast with no evidence of underlying invasive ductal carcinoma or ductal carcinoma in situ of the breast tissue. There was no metastasis in either of the sentinel nodes. Immunohistochemical staining showed a negative expression of oestrogen and progesterone receptors. The patient has not received chemotherapy, radiotherapy or hormonal therapy. The patient has been disease-free for 7 months following surgery.