Local features of the histological structure of malignant glioma tissue are compared with the results of densitometry in computer tomography (CT) with a contrast amplifier. The material for histological examination was collected during stereotaxis biopsy conducted according to CT findings (9 patients) and in examination of the brain of 5 patients who had died without being subjected to operation. The method by means of which anatomical axial sections identical to a series of CT sections were obtained is described. The results in the form of mean values of the coefficients of absorption and the homogeneity of their distribution are shown in accordance with the density of areas with intact brain in each CT section. These data make it possible to detect details of the CT image which are not accessible to visual analysis in some cases and to appraise more objectively the boundaries and spread of the tumors. Besides, they may be used in choosing the targets for stereotaxis biopsy of brain tumors when it is conducted according to the findings of CT. They also increase the informativeness of biopsy.