The paper describes the study of photocatalytic oxidation and antibacterial properties of cotton fabric treated with zinc oxide/silver (ZnO/Ag) nanocomposites. The ZnO nanoparticles were synthesized by an in situ approach on the surface of activated cotton fibers with seeded Ag nanoparticles. The effect of Ag nanoparticles seeding and synthesis temperature on the morphological, thermal, photocatalytic and antibacterial properties of ZnO/Ag nanocomposites treated cotton fibers were characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffractometer, thermo gravimetric analysis, Attenuated Total Reflection-Fourier Transform Infrared spectrometer. Synthesizing ZnO nanoparticles on the surface of un-activated cotton fibers lead to the formation of agglomerated nanoparticles while the Ag nanoparticles seeded cotton fibers prevented forming the same. The results indicated the presence of ZnO/Ag nanocomposites on the coated cotton fabrics, and all loaded samples presented an inhibition zone against S. aureus and E. coli bacteria.