Polymer electrolyte membrane (PEM) fuel cells are considered a promising technology for generating power with water as a byproduct. Recently, sulfonated poly(arylene ether sulfone) (SPAES) has emerged as a most suitable alternative for PEM applications because of its high proton conductivity, high CO tolerance, and low fuel crossover. However, the existing SPAES polymeric membrane materials have poor chemical reactivity, mechanical processability, and thermal usability. Thus, the effects of mixing inorganic nanomaterials with SPAES polymers on proton conductivity, power density, fuel crossover, thermal and chemical stability, and durability are discussed in this review. Further, the progress in preparation methods and fuel cell characteristics by the addition of silica, clay, heteropolyacids (HPA), and carbon nanotubes (CNTs) in polymer membrane materials for PEM applications is also discussed. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.