A microelectrode study is performed of the postsynaptic potentials of single smooth-muscle cells from various regions of cat stomach. The smooth-muscle cells from the region of the fundus, the corpus along the small curvature, as well as from the middle region of the anterior wall, produce more frequently inhibitory responses to transmural electrical stimulation, while the cells of the cardia, of the corpus along the big curvature and the antrum respond predominantly by depolarization and contraction of the muscle strip (excitatory responses). Administration of atropine in doses of 10(-6) M blocks the excitatory postsynaptic potentials, which suggests that the majority of them are cholinergic. By adding adrenergic antagonists in a dose of 10(-6) M it is demonstrated that a part of the inhibitory responses are produced by nonadrenergic inhibitory nerve fibres. The differences in the nerve transmission of different stomach regions may be associated with the possibilities of exercising the reservoir or evacuative function of these regions.