The giant pituitary adenoma surgery remains a real challenge to any neurosurgeon. Despite an extensive development of transsphenoidal techniques, open craniotomy procedures still are required in 5-10% of all cases with pituitary adenoma. The skull base surgery techniques not only allow to minimize the surgery-related trauma of the brain, but also improve the access to the operating field. In the years 1998-2001 the authors operated on the total of 395 pituitary adenoma patients, mostly using the transsphenoidal approach (320 cases), with skull base surgery techniques applied in 75 cases (i.e. in 19% of all patients)--in 67 patients the transbasal-subfrontal approach was applied, and in 2 cases--lateral rhinotomy. There were two indications to the transbasal-subfrontal approach: a large size of the tumor causing visual disturbances, and extension of the adenoma to adherent anatomical spaces. In this group of patients the total removal of the tumour was achieved in 88% of cases. In the remaining patients remnants of the tumor were left in the cavernous sinuses. The skull base surgery techniques are most useful in the treatment of selected patients with pituitary adenoma.