Background: Synchronous Paget's disease of breast and vulva is extremely rare and has only been reported in the literature in one other case. Case: A 58-year-old postmenopausal woman was found to have crusting, bleeding, and discharge from left nipple, as well as vulvar pruritis at the same time. Biopsy of breast lesion demonstrated Paget's disease with an underlying foci of ductal carcinoma in-situ that required total mastectomy of left breast with sentinel node biopsy and breast reconstruction. For vulvar symptoms, the patient was initially diagnosed with dermatitis and topical ointment was prescribed. However, her symptoms persisted for the next several months, and she underwent vulvar biopsy that demonstrated Paget's disease. She underwent partial vulvectomy. Multiple episodes of recurrent vulvar Paget's disease were noted in the postoperative course that medical therapy with Imiquimod and a second partial vulvectomy was performed. Conclusion: Synchronous of breast and vulvar Paget's disease is presented. There was a delay in diagnosing vulvar Paget's disease in this experienced case. While coincidence of breast and vulvar Paget's disease is likely, ectopic mammary tissue in vulvar as well as secondary metastasis from a focal lesion of breast Paget's disease needs to be carefully evaluated whenever the patient complains of vulvar symptoms in the setting of breast Paget's disease.