A systematic study in vitro and in vivo of the antispasmodic agent 2-(diethylamino)-1-methylethyl cis-1-hydroxy (bicyclohexyl)-2-carboxylate (rociverine) showed that its activity is both antimuscarinic and directly muscle-relaxant. The antimuscarinic activity is weaker than that of atropine, N-butylscopolammonium bromide and dicyclomine whilst the direct muscle-relaxant activity is equal to or greater than that of papaverine. The peculiarly balanced ratio of the neurotropic and myotropic components ensures that the antispasmodic effect is the outcome of both, without one prevailing over the other. This not only rules out major atropine-like side-effects but renders rociverine potentially effective on spasm of the different viscera, of particular interest in viscera in which there is only minor involvement of cholinergic structures. The muscle-relaxant activity of rociverine is achieved by inhibiting the availability of Ca2+ at contraction site and not through an antiphosphodiesterasic mechanism, which might explain the absence of muscle-relaxant effects on the smooth musculature of the blood vessels.