Plexiform neurofibromatosis (PN) is a rare manifestation of neurofibromatosis type 1 (NF1). The diagnosis of PN is mainly based on clinical criteria. However, a molecular genetics can be used to find mutations in the NF1 gene to confirm the diagnosis. We report a case of a giant facial plexiform neurofibromatosis associated with RAF1 gain mutation. A 35-year-old man presented to our hospital with a progressive deformity of the lower face that has been begun fifteen years ago. He suffered from a severe symmetrical disfiguration of the lower part face due to overhanging folds of skin pulling down the cheek, lip, and neck skin, mild lagophthalmos on both sides, complete facial paralysis of the affected area.