In this research work, ZnO nanoparticles were produced by pulsed laser ablation method, employing the fundamental wavelength of pulsed Nd:YAG laser of 1064 nm and 7 ns pulse width in deionized water. Four sizes of nanoparticles were produced using different pulse numbers of laser. Simultaneously cotton fabric samples were placed near the Zn target in the ablation container. The ZnO nano particles were in situ synthesized on cotton samples. Characteristics of produced nanoparticles were examined using excitonic absorption peak and Fourier transform infrared (FTIR). X-ray diffraction pattern and dynamic light scattering (DLS) measurement were employed to determine the crystalline structure and size distribution of nanoparticles respectively. Morphology of nanoparticles were observed using Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). Reflection and transmittance spectra of treated cotton fabrics were measured and compared using spectrophotometer. Results show that transmittance of treated cotton is less than untreated one in UVA and UVB region. Also inductively coupled plasma device were used to study the amounts of nanoparticles on the cotton fabrics before and after 20 cycles of washing. Finally, the antibacterial properties of ZnO nanoparticles on Staphylococcus Aureus contaminated cotton fabric were tested. Results show that Staphylococcus bacteria may not survive on the treated textile even after 20 cycles of washing.