Fine needle aspirates of deep white matter, basal ganglia and thalamus from necropsies of three neurologically normal men were compared with two aspirates of cerebral infarcts and with eight aspirates from neoplasms that occurred in the deep cerebrum. Normal white matter contained oligodendroglia with small, dark, round nuclei and astrocytes with larger, bland, oval nuclei and occasional cytoplasmic extensions. Basal ganglia and thalamus contained, in addition, numerous neurons with large nuclei and prominent nucleoli. Recognition of these normal components of the deep cerebral structures is necessary to avoid erroneous diagnoses of neoplasia.