18 patients with "primary empty sella" were reviewed for this study. In 3 of them the sellar enlargement was discovered occasionally by performing skull radiographs for other reasons. The galattorrhea-dismenorrhea or amenorrhea syndrome and obesity were the most common clinical features. Endocrinological tests were normal in ten patients and abnormal in eight. Slight elevation of serum PRL was the most common record. 12 patients had enlarging of the sella turcica; in 4, only the floor was asymmetric and in 2 the sella was quite normal. In 5 patients C.T. without intra-thecal contrast was sufficient to discover the E.S. In 13 patients we performed C.T. cysternography by injecting in the lumbar subarachnoid space 8-10 ml of Iopamidolo 200. This is an excellent and safe technique to perform C.T. cysternography.