A case of fronto-basal traumatism with isolated fracture of the left sphenoidal sinus is reported. Meningitis occured 5, 8 and 11 years, respectively, after injury. Cerebrospinal fluid cranio-nasal fistula was observed at the first time 8 years after injury and remained intermitent in the last 6 years. The surgical technic was accomphished according to the procedure devised by Dietz and consisted of plastics of the anterior floor of the skull accompanied by galea-periosteal junction taken out from the scalp.