The authors report on a series of 188 patients operated upon for pituitary tumour. Since 12 operations were performed because of local recurrence, the total number of operations was 200 : 27 by the intracranial route and 173 by the naso-sphenoidal route. Four deaths (17%) followed surgery by the former route and three (1.8%) by the latter route. During the decade under review surgical indications have decreased for large tumours belatedly diagnosed and increased for micro-adenomas giving rise to endocrine symptoms only, notably prolactin-secreting adenomas. Improved knowledge of histopathology has resulted in the classification being altered : the conventional division into eosinophilic and chromophobe adenomas has been abandoned to be replaced by cellular types corresponding to the various hormone-producing and functional adenomas. Also a new type has appeared : oncocytoma. Secreting adenomas generally have a better prognosis than non-secreting adenomas, would it be only because they are smaller. Technical advances in operations almost exclusively performed nowadays by the naso-sphenoidal route have improved the results with regard to sight. Sight is now improved in 70.5% of the cases and completely restored in 32.4%.