A naphthalene unit-containing bis(ether anhydride), 2,7-bis(3,4-dicarboxyphenoxy) naphthalene dianhydride, was prepared in three steps starting from the nucleophilic nitrodisplacement reaction of 2,7-dihydroxynaphthalene and 4-nitrophthalonitrile in N,N-dimethylformamide (DMF) solution in the presence of potassium carbonate followed by alkaline hydrolysis of the intermediate bis(ether dinitrile) and subsequent dehydration of the resulting bis(ether diacid). High-molar-mass aromatic poly(ether imide)s were synthesized using a conventional two-stage polymerization process from the bis(ether anhydride) and ten aromatic diamines. The intermediate poly( ether amic acid)s had inherent viscosities of 0.95-2.67 dL/g. The films of poly(ether imide)s derived from two rigid diamines, that is, p-phenylenediamine and benzidine, crystallized and embrittled during the thermal imidization process. The other poly( ether imide)s belonged to amorphous materials and could be fabricated into transparent, flexible, and tough films. These poly(ether imide) films had yield strengths of 91-115 MPa, tensile strengths of 89-136 MPa, elongation to break of 11-45%, and initial moduli of 1.7-2.2 GPa. The T(g)s of poly(ether imide)s were recorded in the range of 222-256 degrees C depending on the nature of the diamine moiety. All polymers were thermally stable up to 500 degrees C, with 10% weight loss being recorded above 540 degrees C in air and nitrogen atmospheres.