Composited proton exchange membranes consisting of ZSM-5 embedded in sulfonated poly(ether ketone ether sulfone) (S-PEKES) are fabricated by solvent casting technique in a dispensed zeolite polymer solution. Composite membranes with ZSM-5 content up to 10% v/v exhibit good mechanical properties. The influences of Si/Al and amount of the ZSM-5 on the proton conductivity, methanol permeability, physical properties, and thermal stability of the membranes are investigated. The composite membranes are characterized by FTIR, TGA, LCR meter, and GC techniques. The important properties of the composite membrane are compared with the pristine S-PEKES and Nafion 117 membranes. CBV 2314/S-PEKES composite membrane with 2% v/v ZSM-5 content shows the highest selectivity similar to 2.12 x 10(-5) s.S.cm(-3). (C) 2014 Elsevier B.V. All rights reserved.