Alginate-ZnO nanoparticles (ZnO) composite wound dressing membranes were prepared with two different ZnO concentrations (0.03 and 0.20 g ZnO/g sodium alginate) and cross-linked with two different calcium treatments (low and high Caconcentration) to evaluate the influence of nanoparticle content and cross-linking degree on membrane attributes. ZnO addition did not significantly alter the mechanical properties, water vapor permeability, swelling degree in water and the alginate amorphous nature of the nanocomposite membranes. The increase in cross-linking degree, on the other hand, altered the microstructure of the membranes, increased the tensile strength and reduced the water vapor permeability of the nanocomposite membranes. The presence of ZnO in alginate membranes granted them antibacterial activity in vitro against and and substantially increased the absorption capacity in phosphate buffer and fetal bovine serum solutions, validating their potential use as wound dressings.