Pervaporation is a membrane process that offers high separation performance and has an important potential for the treatment of saline water sources. In this study, poly(vinyl alcohol) (PVA) and PVA-SiO2 nanocomposite membranes were prepared by the solution-casting method, and pervaporative water desalination studies were carried out for synthetic seawater (35 g L-1) at 30, 40 and 50 degrees C. Effects of the temperatures and the incorporation of SiO2 on the pervaporation performance of polymeric nanocomposite membranes were investigated. Membranes were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). In experiments conducted at 50 degrees C, a permeate flux of 4.93 kg m(-2) h(-1) with a salt rejection of 99.3% were obtained. The highest salt rejection was 99.8% at temperature of 30 degrees C. The results showed that the pervaporation performance of PVA membranes was remarkably enhanced with the incorporation of nano-SiO2 into polymeric matrix.