Resveratrol (RSV) is a phytoalexin produced by grapevines. The benefit of resveratrol to health is widely reported. Resveratrol has been found to promote vascular relaxation but its mechanism of action is unclear. Data about an influence of RSV on the contractility of smooth muscles of the uterus are not available. It has been claimed that NO promotes uterine relaxation by the elevation of cyclic GMP. It is generally accepted that NO increases the intracellular cGMP concentration through activation of solubile guanylate cyclase (sGC). The aim of our study were to investigate the effects of RSV on the contractility of rat uterus and to investigate the involvement of the NO–cGMP pathway in the relaxant effect of RSV on spontaneous rhythmic contractions (SRC) and phasic contractions provoked by oxytocin.