Of the 510 patients with pituitary adenoma treated surgically at our hospital in the period 1956-1984 319 were treated by the microsurgical technique, in the period 1973-1984, 235 by transsphenoidal approach and 84 by subfrontal-pterional approach. The transsphenoidal route was used almost exclusively in microadenomas, in intrasellar adenomas, in suprasellar adenomas with midline development, in adenomas invading the sphenoidal sinus and in haemorrhagic adenomas with considerable suprasellar development. In some giant adenomas the transsphenoidal route was used in a first stage operation for debulking the tumour, later removed by transcranial route. The latter route was preferred in large adenomas and especially in adenomas with laterosellar development. In some patients with PRL secreting adenomas post-operative treatment with bromocriptine proved useful when the hormone levels failed to normalize. Post-operative radiotherapy was of value in invasive adenomas and in cases in which tumour removal was not radical.