Nine cases of symptomatic Rathke's cleft cyst are reported. Their most frequent signs and symptoms included headache, chiasmal syndrome and hypopituitarism, while one of the cases developed a sudden onset of headache and vomiting following diabetes insipidus. Endocrinological findings showed a decreased ACTH, gonadotropin and growth hormone more frequently while there were 2 cases of hyperprolactinemia and 1 case of diabetes insipidus. In a neuroradiological examination, a plain skull X-ray showed 5 cases of ballooning of the sella turcica, and a CT scan demonstrated a low to high density of the cyst and 2 cases of marginal enhancement of the cyst. MRI mostly demonstrated a well delineated mass at the sella extending mostly into the suprasellar region and a low to high intensity of the cyst in the T1-weighted image. Two cases were marginally enhanced after gadolinium DTPA administration. The pathological examination, done on 6 cases, showed either single or multiple layers of the epithelium which were mostly ciliated. The epithelium was positive in PAS and Alcian blue in all cases and a histochemical examination showed 3 cases to be positive in EMA and 2 cases positive in CEA. A resection of the cyst wall and an opening of the cyst is thus recommended in symptomatic cases. Therefore, the transsphenoidal approach should be the choice of treatment in an intra- and suprasellar extension of the cysts with sellar enlargement.(ABSTRACT TRUNCATED AT 250 WORDS)