Hyperkeratosis of the nipple and areola is a rare condition. We report a case of hyperkeratosis of the nipple and areola occurrinp in man with no underlying endocrirop thy or synthetic estrogenic drug therapy. The patient was not associated with epidermal nevus orichthyosis and so fitted into the nevoid form of hyperkeratosis of the nipple and areola. The clinical appearance and histological findings of the lesion were the same as those reported before. He showed a slight improvement in the color and hyperkeratcsis of the nipple and areola with 6 months use of a topical keratolytic agent and corticosteroid crearn. (Kor J Derrnatol 1993; 31(2): 249-252)