In the present study, a possibility to realize a transparent sol by zinc-based precursors in a neutral medium without acidic or alkaline catalyst was investigated.Moreover, to study the influence of an inorganic–organic hybrid polymer on the proposed antibacterial finishing, the Zn-based sol was mixed with 3-glycidoxypropyltrimethoxysilane (GPTMS), a hybrid sol–gel precursor, to produce zinc-containing silica coatings on the cotton fibres. An optimization of functionalization process parameters was performed by monitoring survival rate of Escherichia coli bacteria. Finally, selected finishes were tested in respect to their antibacterial activity using potential pathogenic bacteria Staphylococcus aureus and Klebsiella pneumoniae. Sol–gel synthesized cotton finishes based on nano-Zn acetate without and with GPTMS showed larger bactericidal and bacteriostatic activities. The both types of finishes also show hydrophobic effect within the first eliminates the hydrophobicity effect and reduces antibacterial activity. The results are very promising, since the antibacterial activity of cotton is comparably high and the finishing procedure is cheap and can be easily performed.