The one-step hydrothermal synthesis of Pd nanoparticles with RGO-ZnO nanocomposites finds promising applications in antimicrobial, antioxidant, cytotoxicity activities. Synthesized graphene oxide was mixed with ZnO, PdCl4, to form Pd-RGO-ZnO nanocomposite, without using any chemical reductants. Nanocomposite was characterized by several techniques. X-ray diffraction (XRD) and X-ray photoelectron spectroscopic (XPS) analysis confirmed the successful deposition of Pd on the RGO-ZnO sheets. Fourier transform infrared spectroscopy (FT-IR), confirmed the presence of functional groups. Scanning electron microscopic (SEM) observations showed uniform morphology. The SAED patterns of the Transmission electron microscopic studies (TEM) revealed that the prepared Pd-RGO-ZnO nanocomposite patterns were recorded and it was represented to (200), (001), planes which were highly supported by its XRD analysis. Synthesized nanocomposites exhibited excellent performance towards biological activities.