In recent years, nanofibrous mats derived from biopolymers have attracted more interest and attention for biomedical applications, such as wound dressing, tissue engineering, and drug delivery. In this study, carboxymethyl cellulose/Ag nanoparticles (CMC/Ag NPs) nanofibrous membranes were prepared via a simple and green method in which electrospun CMC/poly(ethylene oxide) membranes were immersed in AgNO3 solution, followed by reduction of Ag+-Ag NPs upon ultraviolet (UV) irradiation. Notably, as evidenced by Fourier-transform infrared (FTIR), X-ray diffraction (XRD), and thermogravimetric (TG) analyses, poly(ethylene oxide) was eliminated during the immersion process and CMC nanofibrous mats containing Ag NPs were obtained. The effects of UV wavelength, AgNO3 solution concentration, and irradiation time on the morphology of the CMC/Ag NPs membranes were investigated, revealing optimal parameters (254 nm wavelength, 0.1 mol/L AgNO3 solution, and 10 min irradiation time) under which Ag NPs with average diameter of 20 nm were uniformly distributed on the surface of fibers. Antibacterial tests indicated that the antibacterial efficiency against Escherichia coli and Staphylococcus aureus of the obtained CMC/Ag NPs membranes reached up to 100 %, suggesting great potential for use as antimicrobial dressings.