The occurrence of ectopic breast tissue within the vulva is uncommon and the development of breast carcinoma within vulvar ectopic breast tissue is very rare. To date, only 12 cases of primary vulvar breast carcinoma have previously been reported in the English literature. This paper presents the 13th reported case of primary breast carcinoma of the vulva. The patient presented with a vulvar ulcerated lump and the diagnosis was based on a morphologic pattern consistent with breast carcinoma and the presence of estrogen and progesterone receptors. Primary surgery consisted of radical vulvectomy and bilateral groin dissection. The groin lymph nodes were involved bilaterally. Adjuvant therapy consisted of systemic chemotherapy (4 cycles of adriamycin and cyclophosphamide followed by 4 cycles of paclitaxel) and pelvic radiotherapy. Oral tamoxifen 20 mg/day was started for the next five years. It is concluded that the management of primary breast carcinoma of the vulva should be modeled after that for primary carcinoma of the orthotopic breast with primary surgery followed by systemic chemotherapy and pelvic radiotherapy. Chemotherapy should be similar to that employed for breast carcinoma. Tamoxifen should be prescribed for patients whose tumors contain estrogen receptors.