A novel strategy for the incorporation of carbon dioxide into polymers is introduced. For this purpose, the Ugi five-component condensation (Ugi-5CC) of an alcohol, CO2, an amine, an aldehyde, and an isocyanide is used to obtain step-growth monomers. Polymerization via thiol-ene reaction or polycondensation with diphenyl carbonate gives diversely substituted polyurethanes or alternating polyurethane-polycarbonates, respectively. Furthermore, the application of 1,12-diaminododecane and 1,6-diisocyanohexane as bifunctional components in the Ugi-5CC directly results in the corresponding polyamide bearing methyl carbamate side chains ((M) over bar (n) = 19 850 g mol(-1)). The latter polymer is further converted into the corresponding polyhydantoin in a highly straightforward fashion.