Background. The causal role of the inflammatory process in the central nervous system (CNS) in the pathogenesis of most nervous and mental diseases, as well as in aging, has been established in the last two decades. The most important immune cells in the CNS are microglial cells and macrophages. To date, microglia and macrophages have been studied in various areas of the central nervous system, but have not been studied in the human pineal gland. The purpose of the study was to investigate the morphological features, types and localization of human pineal gland microglial cells using immunohistochemistry. Material and methods. The work was carried out on samples of the human brain pineal gland aged from 16 to 61 years (n=7). An immunohistochemical reaction was performed on sections of the pineal gland using antibodies to Iba-1 and TMEM119, the selective markers of microgliocytes. The frequency of occurrence of immunostained cells was analyzed using statistical methods. Results. It has been established that the majority of phagocytic cells of the structurally normal human pineal gland are not macrophages, but microgliocytes, which are represented by both resting and activated forms. Microglia in the human pineal gland are typically localized in connective tissue trabeculae, both at and away from blood vessels. Microgliocytes are also found in the parenchyma of the pineal gland among the hormone-synthesizing pinealocytes. There was a statistically significant decrease in the number of Iba-1- and especially TMEM119-immunoreactive cells with aging. Conclusion. The present study is the first to examine microglial cells and macrophages in the human pineal gland. The prevalence of microglial cells over macrophages has been established. The morphological features and localization of the identified types of microglial cells indicate their participation primarily in immune defense, and also, probably, in the regulation of pinealocyte functions. In addition, data have been obtained indicating the participation of microglial cells in increasing inflammation in the human pineal gland during aging.