A novel tetraimide dicarboxylic acid was synthesized with the ring-opening addition of 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4,4'-oxydianiline, and trimellitic anhydride in a 1/2/2 molar ratio in N-methyl-2-pyrrolidone followed by azeotropic condensation to tetraimide dicarboxylic acid. A series of poly(amide imide imide)s (PAIIs) with inherent viscosities of 0.8-1.1 dL/g were prepared from tetraimide dicarboxylic acid with various aromatic diamines by direct polycondensation. Most of the PAIIs were readily soluble in a variety of amide polar solvents and even in less polar m-cresol and pyridine. Solvent-cast films had tensile strengths ranging from 99 to 106 MPa, elongations at break ranging from 8 to 13%, and initial moduli ranging from 2.0 to 2.3 GPa. The glass-transition temperatures of these PAIIs were recorded at 244-276 degreesC. They had 10% weight losses at temperatures above 520 degreesC in air or nitrogen atmospheres.