Hyperkeratosis of the nipple and areola, a rarely seen benign dermatosis, is characterized by a verrucous appearance of the nipple and the areola. Females constitute the majority of the cases, however, there are also rare reports of male cases. On clinical examination, hyperkeratotic and hyperpigmented plaques are located on the nipple and/or areola. No erythema or induration is observed on the affected skin. According to a widely adopted classification system, primary hyperkeratosis of the nipple and areola is divided into three groups as type 1 which is coincidentally associated with keratinization disorders such as ichthyosis and Darier's disease; type 2 which is associated with hormonal factors or systemic diseases; and type 3 which is entirely considered an idiopathic form. Idiopathic form often affects female patients in the second or third decade of life and occurs spontaneously. Patients often present due to cosmetic reasons. The etiology of this condition has not been fully elucidated and, to date, various treatment methods have been attempted. Herein, we report two female cases (25-year-old and 14-year-old) of idiopathic hyperkeratosis of the nipple and areola based on the clinical and histopathological examination.