Starting from some new 2,5-disubstituted-1,3,4-oxadiazole difluorides, synthesized by cyclocondensation of dihydrazides with 4-fluorobenzoic acid, novel poly(arylene ether)s were prepared by halo displacement polymerizations with bisphenol A in the presence of potassium carbonate. Model reactions demonstrated the unsuitableness for halo displacement reactions of the difluoride containing the SO2 group. The synthesis and characterization of polymers are discussed and the thermal properties are compared with those of other polymers reported in literature.