The surface modification in order to obtain hydrophobic cotton fabrics was carried out using air/HMDSO Gliding Arc plasma discharge. The dependence of the surface wettability on used process parameters, such as air flow, sample distance and treatment time were investigated. The wettability of cotton fabrics was evaluated by the drop test method by measuring the time of droplet absorption and water contact angle (WCA). The changes in the surface morphology were examined by optical microscopy and scanning electron microscopy (SEM). The treated hydrophobic fabrics were subjected to the analysis of chemical composition of the applied coatings using the ATR-FTIR spectroscopy. Hydrophobic cotton fabrics were obtained, especially with a high resistance to static wetting. In addition, the treated cotton fabrics were tested using a spray test measurement and were subjected to multiple washing.