Aim of the study was to discover specific features of linear blood velocity in early postoperative period in patients with tumors of chiasmatic-sellar region. Measurement of linear blood velocity using transcranial duplex sonography was performed in 294 patients with tumors of hypothalamo-hypophyseal area (149 suprasellar pituitary adenomas, 145 endosuprasellar, hypophyseal and ventricular craniopharyngiomas). It was found that vasospasm of different severity was present in 62% cases after surgical removal of chiasmatic-sellar region tumors. This "primary vasospasm" was associated with intraoperative damage to a vessel. Delayed angiospasm was caused by subarachnoid hemorrhage into basal cisterns due to hyperactivation of neuroendocrine systems of adenohypophysis and aldosterone. Persistent vasospasm with linear blood velocity over 200 cm/s results in irreversible ischemic damage of subcortical and hypothalamic structures.