Epidermal cyst in the fibroadenoma of the breast is very rare. A 29-year-old woman presented with a lump in the upper outer quadrant of the right breast. Clinically it was a fibroadenoma and the excisional specimen showed an encapsulated, firm lobulated lesion with a cystic area on cut surface. The cystic area showed squamous metaplasia of the ductal epithelium and keratinous cyst formation in the fibroadenoma. We report this unusual case with review of literatures.