We studied the effect of intracerebral transplantation of bone marrow mesenchymal stem cells on microcirculation (density of microvascular network and reactivity of arterioles) in the pia mater of 2-3-month-old rats. It was found that after transplantation of mesenchymal stem cells, the density of pial microcirculatory network in the contralateral hemisphere significantly increased (by 1.7 times; p<0.05) in comparison with both intact animals and controls. The number of arterioles in the studied area increased most markedly (by ≈2.5 times; p<0.05) in comparison with other groups. Intracerebral transplantation of mesenchymal stem cells or conditioned culture medium (α-MEM) had no effect on reactivity of pial arterioles.