Genital melanosis is an acquired, irregular, brown to black discoloration of the glans or shaft of the penis, or of the vulva and vagina. Although genital melanosis seems similar to malignant melanoma clinically, the histologic findings of genital melanosis show basal layer hyperpigmentation with or without melanocytic hyperplasia and no atypia of the melanocytes. We report a rare case of genital melanosis ; a vulvar melanosis.