Present and potential applications of scanning electron microscopy (SEM) to the study of solid neoplasms, the lining of cysts, exfoliated cells, mineral deposits, and supporting tissues of the central nervous system (CNS) are discussed. Special features of the SEM image include a large field of view and depth of focus, high resolution, and a three-dimensional impression of surface topography. These features have contributed a clearer understanding of similarities between colloid cyst and olfactory epithelium. They demonstrated differences between glial and nonglial fibrils of selected CNS neoplasms. These features may ultimately enhance detection, diagnosis, and study of neoplastic origins and spread within the CNS and cerebrospinal fluid. Special features of tissue examination by SEM include processing without the need of thin sections and elemental analysis by X-ray spectroscopy. These features have been applied to studies of calcium and thorium associated with meningiomas and a schwannoma.