Abstract Various p-substituted benzamidinium formates (I), acetates (II), trifluoroacetates (III) and pyruvates (IV) were prepared and the nature of the amidinium-carboxylate interactions were examined by 1 H and 13 C NMR spectra. The spectroscopic data are consistent with the presumption that the carboxylic part is only slightly influenced by the diverse substitution of the aromatic benzamidinium ring.