Comparison between the macroscopic order (inferred from surface pressure/area isotherms and fluorescence microscopy) and the molecular order [determined by infrared reflection-absorption spectroscopy (IRRAS)] for N-acylamino acid monolayers shows that hydrogen bond formation via the NH, COOH, and p-hydroxyphenyl groups, respectively, may lead to pronounced chiral discrimination. On a pure water surface, N-hexadecanoylalanine films exhibit preferential homochiral interactions, which may be strengthened by Pb2+ in the aqueous subphase, while Zn2+ disturbs this structure and suppresses the chiral discrimination. In N-octadecanoyltyrosine and N-octadecanoyltyrosine methyl ester monolayers, both homo- and heterochiral discrimination may be observed, depending on the available area per molecule, where the free fatty acid carboxyl group gives rise to additional film compression and, thus, to a higher conformational order for the alkyl chains. However, in the presence of both PbCl2 and ZnCl2 in the aqueous subphase, the pronounced chiral discrimination effect disappears. Analysis of the methylene scissoring delta(CH2) bands shows that the different effects of Pb2+ and Zn2+ cannot be explained on the basis of different subcell structures (in both cases an orthorhombic structure is prevailing), but on the basis of different complex formations between the bivalent cations and the carboxylic acid headgroup as inferred from the separation Delta between the antisymmetric and the symmetric carboxylate vibrations, Delta = v(a)(COO) - v(s)(COO). The results summarized in the present paper suggest that theories like Andelman’s tripode theory should be expanded to account for potential metal complex formations.