Abstarct: Given the serious threat of antibiotic resistance and the limitations of conventional antibiotics, this study investigates the simultaneous effects of silver (Ag) decoration and incorporation of multi-walled carbon nanotubes (MWCNTs) into zinc oxide (ZnO) nanostructures as a novel alternative with enhanced antibacterial performance. Ag-decorated ZnO/MWCNT nanocomposites were synthesized via a hydrothermal method, and their structural, optical, and antibacterial properties were examined. XRD analysis confirmed the wurtzite structure of ZnO and the presence of silver. FESEM images showed that increasing the MWCNT content led to more uniform distribution of ZnO particles, while excessive MWCNTs caused nanotube agglomeration. Raman spectra indicated the structural stability of ZnO and stress induced by Ag and MWCNT incorporation. DRS analysis revealed a gradual decrease in the band gap and improved visible light absorption with increasing MWCNT content. PL spectroscopy demonstrated reduced electron – hole recombination and enhanced optical properties. Antibacterial activity, evaluated via disk diffusion and microdilution methods, showed that ZA and ZAC1 samples exhibited the highest inhibition against Escherichia coli and Staphylococcus aureus, respectively, while higher MWCNT contents had a negative effect. These findings indicate that an optimized combination of ZnO, Ag, and MWCNT can lead to nanocomposites with enhanced optical and biological properties. Furthermore, ZnO:Sb nanocomposites were synthesized and characterized at different atomic percentages of antimony. XRD results showed a reduction in crystallite size and structural modifications with increasing Sb content. DRS analysis confirmed a decrease in the band gap due to Sb doping, while PL spectra revealed reduced recombination intensity. These results highlight the high potential of ZnO:Sb nanostructures for antibacterial and photocatalytic applications.