In this work two nanocomposite - Nafion® membranes, containing 2 and 4% of TiO 2 with an average size of 10 nm were recasted. According to the scanning electron microscopy - Energy dispersive spectroscopy (SEM-EDS) structural analysis, the composite Nafion®/TiO 2 membranes had a two layer - structure, one layer enriched with the ceramic particles, and the other less concentrated but well dispersed. The ethanol crossover rate through these membranes and swelling degree at different temperatures and different concentrations has been investigated and compared with unmodified Nafion® membrane. The experimental results show that the swelling degree of these membranes gets higher as ethanol solution concentration and temperature increases and the same results were obtained for the ethanol crossover rate increases. The water swelling is increased either what would allow higher working temperatures and lower relative humidity and improve the fuel cell performances.