The effect of water-soluble form of quercetin on the structural changes of glial cells in hippocampus was investigated in mice after repetitive mild traumatic brain injury. Reactive astro- and microgliosis in hippocampus were observed after brain injury. Iba-1 and GFAP immunohistochemistry was used to visualize astrocytes and microglia cells. Immunopositive cells were counted in hippocampal CA1-area at 5th, 10th and 30th days since the first injury and at 5th, 10th and 30th days since the first quercetin injection. Administration of quercetin leaded to the decrease in number of activated glial cells. Thus, our study demonstrates the following: repetitive mild traumatic brain injury in mice is associated with reactive gliosis; quercetin showed neuroprotective effects by reducing this gliosis. In view of the described, use of quercetin is appropriate for pharmacological correction of cerebrovascular disorders after traumatic brain injury.