Zinc oxide (ZnO) thin films were deposited onto glass substrates by radio frequency (RF) magnetron sputtering using a metallic zinc target. Zinc oxide films were prepared in two different gas atmospheres; in the first set, helium and oxygen gas flow ratio (He:O-2) was varied from 87.5% to 37.5%. In the second set of experiment, oxygen flow rate was kept constant at 2.5 sccm while argon and helium gas flow ratio (Ar:He) was varied from 9.0% to 87.5%. The structural, wettability, and optical properties of ZnO films were investigated by X-ray diffractometry (XRD), contact angle measuring system, and UV-vis-NIR spectrophotometer. The XRD results show increased preferred orientation along (002) plane for deposited ZnO films in both cases. The average crystallite size of ZnO films increases with increase in gas ratio for both set of experiments. The deposited films are hydrophobic by nature for water and ethylene glycol. Optical transmittances greater than 60% were observed in the wavelength interval from 450 nm to 650 nm for both cases. (C) 2016 Elsevier B.V. All rights reserved.