Surface wettabilities of the nano-ZnO/P(MMA-co-BA) nanocomposites before and after hydrothermal treatment were investigated by water contact angle (Dataphysic OCA20) measurements performed by the static sessile drop method. A 10 mL double distilled Milli-Q water droplet was gently placed on the sample surface using a micro-syringe and a mean value of contact angle was calculated from at least ten individual measurements.