This article presents an abstract of the research paper "Possibilities of CNS Pathologies Diagnosis on the Basis of Ultrasmall Samples Collected During Stereotaxy," which was discussed in the 13th Conference of the Polish Association of Neuropathologist. According to the paper, the key for decision made during stereotactic biopsy (SB), concerning the selection of treatment option, is the histological diagnosis. Between December 2000 and December 2003, 111 stereotactic procedures were performed, based on the system of stereotactic planning. It was found that SB permitted diagnosing deep located brain cancers.