Neurofibromatosis (NF) is a dysplastic disease which consists of multiple café-au-lait spots and neurofibromas from neural sheath. The 61-year-old male patient complained of sudden severe pain on the left buttock started one month ago. On physical examination, multiple "lentigines" were seen on his left buttock which spreaded to the thigh and small soft protruding nodules were observed on the right side of the back and left shoulder. Histopathologic finding of a specimen obtained from a nodule was consistent with neurofibroma. Magnetic resonance imaging (MRI) and ultrasonography revealed asymmetrical hypertrophy of neurovascular bundle located in the left greater sciatic foramen. On diagnosing as NF, he was treated with medication, physical modalities and therapeutic intervention (caudal block). Visual analogue scale (VAS) went down to 3/10 with these treatments and he was discharged. We report successful treatment of buttock pain rarely associated with segmental neurofibromatosis. (J Korean Acad Rehab Med 2009; 33: 639-643)