Hyperkeratosis of the nipple and areola is a rare condition; its characteristic properties are verrucous thickening and brownish discoloration of the nipples and areola. The nevoid form of the disease is extremely rare, usually seen in women in the second or third decade of life. The nipple is seldom affected alone. We report two cases of the nevoid form of hyperkeratosis of the nipple. In both female patients, lesions developed after puberty and were confined to both nipples alone. One of the patients' lesions became darker and more verrucous during pregnancy, making breast feeding impossible.