The problem of competitive metal ion binding to poly(alkylene phosphate)s, considered as synthetic models of natural teichoic acids, was analysed theoretically applying the Poisson‐Boltzmann (PB) equation to a cylindrical cell model. There were calculated the radial distribution functions as well as the degree of ion binding of mono‐and divalent metal ions to polyphosphate ions in solutions of different concentrations ranging from 10−5 M to 10−2 M and containing different amounts of M⊕ and M2+ counterions. For comparison, analogous calculations were performed also for poly(styrenesulfonate)s. The results indicate the preferential binding of divalent metal ions to polyphosphate ions over monovalent ones. The selectivity for M2+ ions is concentration dependent and increases with decreasing the polymer solution concentration. It results from PB calculations, that condensation of divalent metal ions at the surface of polyion chains seems to be responsible for preferential binding of biologically important metal ions, for example magnesium, to natural teichoic acids and their synthetic analogues.