The group of 102 patients with chronical CSF rhinorrhoea which have been operated on for osteodural damage is a rare diagnosis compared to the total number of craniocerebral injuries. In a number of cases, clinically apparent or latent CSF rhinorrhoea has been complicated by meningitis; often meningitis recovers. Minor head injuries which have not attracted patient's attention have misled doctors at recognizing the causal consequential connection of meningitis and a head injury.