In the present study, composite film was prepared by blending neem leaf extract with a selected concentration of nanocomposite silver and zinc and its characterization. Silver nitrate and zinc oxide were used as precursors for the nanocomposite of Ag-Zn synthesis. Neem leaves consist of various phytochemicals, polyphenols, and quercetin which help in the reduction of the chemical salt into the nanoparticles and act as the capping agent. Our result showed that the nanocomposite of Ag-Zn nanoparticles was grey. UV spectroscopy shows the maximum peak at 423nm. The average crystallite size reported for nanocomposite Ag–Zn Np was 35.38 nm. The antioxidant activity was enhanced up to 88.15%. Homogeneous growths on the surface were shown in SEM images of Ag-Zn Np. Also by using chitosan and guar gum composite films modified with Ag-Zn nanoparticles for packaging. The distribution of Ag-Zn nanoparticles in films was uniform. Ag-Zn NPs loaded films were constructed by a simple solvent casting method and were found to be polished smooth and flexible. Transparency, tensile strength, and opacity increased. WVTR and WVP value was lowered. Tensile strength increases due to the presence of microfibers and polyphenols in the neem leaf extract and elongation at break decreases as the increase in the compatibilization between the polymers reduces the flexibility of film.