The goal of the study was to identify the subependymal microglial cells of the III ventricle of the rat brain and to determine their structural characteristics. The sections of the brain of intact Wistar (n=3) and Sprague-Dawley (n=3) male rats were studied using the methods of immunocytochemistry and confocal laser microscopy. Subependymal microglia of the III ventricle was found to be a constantly present cell population. Two types of subependymal microgliocytes were identified - spindle-like and basket cells. Their processes penetrate the ependymal layer and reach its surface, thus contacting the cerebrospinal fluid (CSF), which suggests a possible participation of these cells in the structure of CSF-brain barrier.