In the introduction the authors deal with nasal liquorrhoea in general, with its diagnosis and treatment. The main part in the diagnosis of nasal liquorrhoea is played by X-ray examination, CT cisternography. This is followed by the case-record of a 53-year-old female patient with a three-month spontaneous non-traumatic liquorrhoea. The fistula was closed using a neuro- surgical intradural approach.

        Key words: spontaneous nasal liquorrhoea, beta 2 transferrin, CT cisternography, intra/extra- dural plastic operation.