New styryl amidines have been found to be the first easily polymerizable amidine monomers. The effect of incorporation of these amidines in copolymers and the use of amidinium groups as binding sites in molecularly imprinted polymers are briefly reviewed. The Figure represents a microcavity imprinted by the polymerization of one of the new bisamidinium styryl salts with a transition-state-analogous template.