Composite membranes were prepared from polybenzimidazole, based on 3,3',4,4'-tetraaminodipheniloxide and 3,3-bis(p-carboxyphenil)phtalide (PBI-O-PhT), and silica or zirconia by two different methods (in situ synthesis and the casting with the use of preliminarily synthesized particles). It was shown that the membrane modification resulted in ion conductivity increase in the investigated temperature range (20-180 degrees C). The conductivity value runs up to 0.162 S cm(-1) at 180 degrees C. The membrane modification by hydrated oxides resulted in better acid retention in the membrane matrix in comparison with the unmodified membrane. (C) 2010 Elsevier B.V. All rights reserved.