We observed 17 cases of cafe au lait spots histopathplogi ally. Out of 17 cases, 9 cases were neurofibromatosis with neurofibromas, 6 cases were neurofibromatosis without neurofibroma, and 2 cases were normal healthy persons. The results were as follows. l. In all 17 cases, melanin pigment was increased in melanocytes and keratinocytes. 2. Griant pigment granules were identified only in 3 cases of neurofibromatosis with neurofibromas.