Seventy-four patients with tumors in the sellar region were examined by means of encephalotomography and axial computerised tomography. In nearly all cases, the localisation and expansion of tumors could be exactly determined by encephalotomography. In addition, a graduation according to the degree of hypothalamic compression was possible. In cases of density differences between tumor and brain tissue and contrast enhancement more information of the inner structure of a tumor (cystic or solid) could be obtained by computerised tomography. But in cases of missing density differences or/and contrast enhancement tumor diagnosis is easier by encephalotomography because of the high efficiency of encephalotomography. The indication for the form of operative treatment, transsphenoidal or transcranial, depends on the exact knowledge of tumor growth, especially of the degree of hypothalamic compression. Therefore, in all uncertain computerised diagnosis encephalotomography has to be undertained.