The introduction of pendant, reactive groups into polyurethane macromolecules is a challenging problem. A variant of the nondegradative modification of polyurethanes with epoxy groups attached to the urethane sites is proposed. Two types of commercial elastomeric segmented polyurethanes, represented by a poly(ether urethane) and a poly(urethane urea), were functionalized. by base-induced N-glycidylation of the urethane hard segments with an excess of epibromohydrin in dimethylacetamide solutions at low temperatures. This resulted in the modification of polymers with 0.30-0.44 mmol/g of pendant epoxy groups. Lithium or potassium tert-butoxides were used as bases to initiate the reaction. A nonpolymeric urethane model (ethyl N-p-tolylcarbamoate) was used to verify the course of glycidylation. One of the polymers was subjected to epoxy ring opening with 1-propanethiol, demonstrating the versatility of pendant glycidyl groups as auxiliary groups for further bulk modifications of polyurethanes. These functionalized polyurethanes are useful for the further covalent attachment of suitable moieties (stabilizing or biocompatibility-enhancing agents).