Poly(arylether benzoxazole)s (PAEBOs) were prepared from a series of fully aromatic dicarboxylic acids containing (phenylenedioxy)diphenylene or (naphthalenedioxy) diphenylene groups and 3,3'-dihydroxy-4,4'-diaminobiphenyl (I) or 4-4'-(hexafluoroisopropylidene)bis(2-aminophenol) (II) through high-temperature direct polycondensation. A phosphorous pentoxide/methanesulfonic acid mixture or trimethylsilylpolyphosphate was used as a condensing agent. All the PAEBOs were amorphous and soluble in strong acids, and those derived from II were also readily soluble in polar organic solvents. Flexible films were cast from their chloroform solutions. The PAEBOs showed inherent viscosity values of 0.68-2.06 dL/g (CH3SO3H, T = 30 degrees C, c = 0.15 g . dL(-1)). Thermal analysis indicated glass-transition temperatures ranging from 236 to 270 degrees C and thermal stability (5% weight loss) in nitrogen up to 526 degrees C.