The properties of hybrid membranes based on a perfluorosulfonated Nafion polymer and hydrated titania are described. The membranes have been prepared by casting from a solution containing particles of a dopant preformed by precipitation at different pH values or a precursor for further synthesis of titania. The dependence of the conductivity of these samples on relative humidity and temperature has been studied. Modification leads to an increase in the proton conductivity of the membranes; higher values are obtained for the samples prepared using preformed TiO2 particles. It has been shown that the background of the dopant has an effect on the conductivity value: at low relative humidity, higher values are obtained using titania with a higher degree of hydration. The introduction of small amounts of the dopant (1.5-3 wt %) leads to an increase in the cation transport selectivity compared to that of the unmodified membrane.