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Biohybrid polyurethane-grafted-chitosan hydrogels were synthesized by aheterogeneous synthetic method. Chitosan-grafted polyurethane hydrogels wereprepared. Their analogous, without chitosan, were studied as control.Hydrogels were prepared using bis(cyclohexyl)methane-4,4’-diisocyanate, 1,4-butanediol, a crosslinking agent and, alternatively, polyethylene-oxide orpolyethylene-adipate as macrodiol. Chitosan powder, in a preset molar ratio, wasadded to the reacting mixture. Structure and thermal properties were investigatedby FT-IR, DSC and dynamic mechanical analyses (DMA).The obtained biohybrid hydrogels show interesting structural characteristics: theinsertion of chitosan in the polymeric structure induced an increase of swellingdegree, modification of the structure (by FTIR), and thermal properties (by DSCand DMA). DMA analyses, performed on dry and swollen state, showed asignificant increase of storage modulus with the insertion of chitosan; swellinginduced a decrease of the storage modulus. Obtained results indicate thepossibility to produce a range of materials with substantially different propertiesto be targeted to different applications.