Current study reports the facile synthesis, in-vitro characterization and antibacterial efficacy of novel moxifloxacin (Mox)-loaded chitosan-pullulan-silver-nanocomposite (CSPN) films. Chitosan and pullulan have been notably practiced as stabilizers together with sodium borohydride (NaBH4) utilized as mediator for in-situ silver nanoparticles (AgNPs) synthesis under environment-friendly conditions using aqueous mixture of both polymers. The nanocomposite films served as a promising carrier system for model antibacterial i.e. Mox. The films were prepared via conventional solvent casting of aqueous composite suspension containing Mox. The fabricated nanocomposites were screened for surface plasmon resonance (SPR) peak and nanometric size of AgNPs via UV–Vis spectroscopy and zeta sizer. The fabricated nanocomposites were characterized for surface morphology (SEM), elemental composition (EDX), functional group interactions (FT-IR), structural/crystallinity modifications (XRD) and thermal stability using TGA and DSC tests. The nanocomposites were investigated pharmaceutically for mechanical, swelling, water contents and water solubility, drug release, drug permeation and antibacterial characteristics. The formed AgNPs displayed SPR peaks at 409–425 nm and exhibited particles size below 165 nm. The AgNPs and Mox were well embedded and uniformly dispersed within the composite. The ternary nanocomposites with controlled swelling and improved water solubility were successfully synthesized offering sustained drug release and permeability. The synthesized Mox-loaded CSPN films presented considerable antibacterial efficacy against P. aeruginosa and MRSA (clinical strains). The incorporation of pullulan into the composite improved its bactericidal effectiveness against P. aeruginosa and MRSA owing to prolonged Mox and silver release. Our findings suggest that the formulated ternary nanocomposites are promising biomaterial for drug delivery. © 2019 Elsevier B.V.