The present work formulates a general expression for the effect of the kinetics of association/dissociation of chemically heterogeneous metal complexes on polarographic curves and discusses the best numerical strategy to simulate them. The concepts are based on standard de and pulse polarography. The treatment holds for (i) Freundlich-type of metal-ligand binding; (ii) different diffusion coefficients of complexed and uncomplexed species; (iii) an overall excess of ligand; and (iv) an association rate constant invariant for a given type of metal ion.