Hydrogels have been considered as promising materials in tissue engineering and biomedical areas. However, the weak and brittle nature of common synthetic hydrogels largely hinders their potential applications. Therefore, it is challenging to fabricate tough hydrogels for biomedical applications. In this manuscript, well-defined and thermo-responsive polyurethane-poly(ethylene glycol) (PU-PEG) hydrogels were prepared via thermally-induced copper-catalyzed 1,3-dipolar azide-alkyne cycloaddition (CuAAC) using azido-pendent PU-PEG and dialkynyl PEG as the gel precursors. The physical properties of the as-formed hydrogels were investigated by swelling ratios and mechanical tests. The PU-PEG hydrogels not only possess thermo-responsive and excellent mechanical properties, but also exhibit good biocompatibility.