<p>The development of advanced wound dressings that mimic the extracellular matrix is crucial for effective wound management. While electrospun polyurethane (PU) offers proper mechanical properties and void fraction, integrating bioactive natural polymers is key to enhancing its performance. This study introduces a central innovation: a covalently-linked nanocellulose-chitosan hybrid nanocomposite, designed to synergistically combine the mechanical strength of cellulose nanowhiskers with the inherent antibacterial and biocompatible properties of chitosan. This hybrid was successfully incorporated into PU nanofibrous mats via electrospinning. The resulting scaffolds underwent characterization through scanning electron microscopy, tensile testing, void fraction assessment, and measurement of the water vapor transmission rate. The biocompatibility and safety of the composite nanofibers were validated using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay. The composite scaffolds exhibited outstanding functional properties, including an optimal water vapor transmission rate (WVTR ≈ 2242&#xa0;g/m²/day) for maintaining a moist wound environment, and significantly enhanced antibacterial activity, forming inhibition zones of 15.2 ± 0.8&#xa0;mm for <i>E. coli</i> and 17.5 ± 0.6&#xa0;mm for <i>S. aureus</i>. Critically, the mats demonstrated biocompatibility, supporting cell viability greater than 95% in MTT assays. These findings collectively confirm that the PU/nanocellulose-chitosan hybrid nanofibrous mats are a multifunctional candidate for wound dressing applications.</p>