Abstract: The occurrence of primary breast cancer of the vulva is extremely rare (24 cases described in the English-language literature). We report a case of a primary breast carcinoma of the vulva. An 82-year-old woman presented with a nodule of the left labia minor, which was excised. The histologic examination revealed the presence of adenocarcinoma of mammary origin, positive for common breast markers and for estrogen and progesterone receptors. The study for orthotopic breast carcinoma was negative, as well as the study for metastatic disease. The diagnosis of primary breast carcinoma was established. Our patient was then submitted to pelvic and inguinal radiotherapy as well as an aromatase inhibitor (letrozole), and she remained completely asymptomatic. Because of the rarity of this condition, guidelines for therapy are unavailable. The management suggested in the literature is that of primary orthotopic breast neoplasm of a similar stage.