ZnO nanoparticles (ZnO-NPs) were prepared by sonochemical method at room temperature and were applied on to the 100 % cotton woven fabric using in situ and pad-dry cure methods. The results show that nanoparticles with average sizes of 20–100 nm with different morphologies have been created on the surface of samples. Synthesis of ZnO-NPs was varied in the morphological transformation by changes in zinc acetate dehydrate concentration. Characterizations were carried out using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Spectrophotometery. The antibacterial activities of the fabrics were assessed semi-quantitatively by the colonies count method. The results show that the finished fabric demonstrated significant antibacterial activity against S.aureus in antibacterial test.