Porokeratosis of Mibelli, a disorder of keratinization, should be treated because of the possibility of development of malignant epithelial tumors on the porokeratotic lesions. Liquid nitrogen cryosurgery is considered to be particularly useful in the treatment of precancerous and benign skin lesions. We aimed to evaluate the efficiency of this method in the treatment of porokeratosis of Mibelli. Eight patients with 20 porokeratotic lesions were treated with spray cryosurgery. Each lesion was frozen for 30 seconds with a spray tip after the keratotic borders were removed conically by sharp dissection. Eighteen of the 20 lesions were healed successfully with slight atrophy in one session. One more session was necessary for the other two lesions. Liquid nitrogen cryosurgery may be considered superior to other destructive methods in the treatment of porokeratosis of Mibelli, with advantages such as simplicity, high cure rates, low cost, short treatment period, and few complications.