A new aromatic sulfone ether diamine was synthesized by nucleophilic aromatic substitution reaction of 5-amino-1-naphthol with bis(4-chlorophenyl) sulfone in the presence of potassium carbonate in a polar aprotic solvent. Polycondensation reactions of the obtained diamine with pyromellitic dianhydride (PMDA), benzophenonetetracarboxylic dianhydride (BTDA), and hexafluoroisopropylidene diphthalic anhydride (6FDA) resulted in preparation of thermally stable poly(sulfone ether imide)s. Poly(sulfone ether amide)s also were prepared by reaction of the diamine with terephthaloyl chloride (TPC) and isophthaloyl chloride (EPC). The prepared monomer and polymers were characterized by conventional methods. Physical and mechanical properties of polymers, including thermal stability, thermal behavior, solution viscosity, solubility behavior, and modulus, also were studied.