Three cases with germinoma in the region of the pineal body diagnosed by means of computer tomography are described. The diagnosis was verified in all of them during operation. Computer tomography demonstrated three-dimensional structures with irregular contours in the posterior parts of the third ventricle which was seen more clearly after injection of the contrast medium. Petrifaction was found in the center of the pathological structure in all cases. The diagnostic value of computer tomography from the standpoint of the localization of the tumor is emphasized.