The Falck-Hillarp method was used to study adrenergic (sympathetic) innervation of the veins and lymphatics in the microcirculatory bed of the rat mesentery. It was ascertained that innervation of these vessels is realized by side branching of the periarterial adrenergic plexuses. While being in contact with adjacent venous and lymphatic vessels, they form in the latters' wall perivenous and perilymphatic adrenergic plexuses. It is noted that adrenergic innervation of venous and lymphatic microvessels is ununiform and focal in nature. The results allow one to consider the periarterial adrenergic plexuses as a fundamental source of innervation of veins and lymphatics of the mesenterial microcirculatory bed.