This study involved the synthesis of CuWO4/Co3O4 nanocomposites using hydrothermal technique for catalytic reduction of organic pollutants and antibacterial applications. The physicochemical characteristics and the morphological features of the prepared nanocomposites were investigated by different techniques including Xray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM), Xray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy (HRTEM). The XRD, FTIR, XPS analysis confirmed the successful loading of CuWO4 on the surface of Co3O4. The magnetic properties of the nanocomposites were found to be lower than that of pure Co3O4. The TEM analysis results revealed that pure Co3O4 and 1 % CuWO4/Co3O4 nanocomposites had semi-spherical particles with average diameters of 73.9 and 69.6 nm, respectively. The catalytic activity of pure Co3O4 and the nanocomposites were conducted for the reduction of various organic substances in simulated water involved 4-nitrophenol (4-NP), Congo red (CR), methylene blue (MB), and rhodamine B (RhB) in the presence of NaBH4. The 1 % CuWO4/Co3O4 nanocomposite showed the best catalytic reduction performance for 4-NP, achieving full reduction in 6 min with a rate constant value of 0.67 min− 1 . In addition, this nanocomposite also showed good catalytic performance in the reduction of 4-NP in real samples including juice and milk. Moreover, the antibacterial activity of the prepared nanocomposites was evaluated against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), and Staphylococcus epidermidis (MRSE). The 10 % CuWO4/Co3O4 nanocomposite showed the best antibacterial action among the other nanocomposites.