The rise of multidrug-resistant bacteria and the growing prevalence of cancer need the creation of novel treatment approaches. This work aims to do a green synthesis, characteriszation, and assessment of silver (Ag), zinc (Zn), and silver-zinc (Ag-Zn) nanoparticles using Gum Arabic as plant extract. The objective is to assess the antibacterial and anticancer properties of these nanoparticles. Nanoparticles were produced by using an aqueous extract derived from plant leaves, which had dual properties as both a reducing and stabilizing agent. To investigate the structural, optical, and morphological features of the produced nanoparticles, UV-Vis spectroscopy, Fourier-transform Infrared (FTIR) spectroscopy, X-ray Diffraction (XRD), and Transmission Electron Microscopy (TEM) were used. The agar well diffusion and broth microdilution techniques were used to evaluate the antibacterial activity of the nanoparticles against Staphylococcus aureus and Escherichia coli. The antineoplastic effects were assessed in MCF-7 (breast cancer) and HepG2 (hepatic cancer) cell lines by MTT assay. To clarify the mechanism of action, the production of reactive oxygen species (ROS) was also quantified.  Ag, Zn, and Ag-Zn nanoparticles were successfully synthesized, with UV-Vis spectroscopy confirming the formation of nanoparticles at characteristic peaks (Ag NPs ~410 nm, Zn NPs ~370 nm, Ag-Zn NPs ~390 nm). XRD analysis indicated crystalline structures, and TEM revealed spherical shapes with sizes ranging from 12 to 20 nm. The Ag-Zn nanoparticles exhibited the highest antimicrobial activity, with the largest zones of inhibition (up to 20 mm) and the lowest MIC values. In vitro anticancer assays showed that Ag-Zn nanoparticles significantly reduced cell viability (down to 20%) and induced apoptosis (up to 60%) in MCF-7 and HepG2 cells. ROS generation assays revealed that Ag-Zn nanoparticles caused the highest levels of ROS, correlating with increased cytotoxicity and apoptosis. The study demonstrates the successful green synthesis and characterization of Ag, Zn, and Ag-Zn nanoparticles, with Ag-Zn nanoparticles showing superior antimicrobial and anticancer activities. These findings suggest that Ag-Zn nanoparticles synthesized via plant-mediated methods could serve as promising candidates for developing new antimicrobial agents and cancer therapies. Further studies should explore in vivo efficacy and safety to facilitate clinical applications.