Three new bis(ether-acyl chloride) monomers, 1,1-bis[4-(4-chloroformylphenoxy)phenyl]cyclohexane (1a), 5,5-bis[4-(4-chloroformylphenoxy)phenyl]-4,7-methanohexahydroindan (1b), and 9,9-bis[4-(4-chloroformylphenoxy)phenyl]fluorene (1c), were synthesized from readily available compounds. Aromatic polybenzoxazoles bearing ether and cardo groups were obtained by the low-temperature solution polycondensation of the bis(ether-acyl chloride)s with three bis(aminophenol)s and the subsequent thermal cyclodehydration of the resultant poly(o-hydroxy amide)s. The intermediate poly(o-hydroxy amide)s exhibited inherent viscosities in the range of 0.35-0.71 dug. All of the poly(o-hydroxy amide)s were amorphous and soluble in many organic polar solvents, and most of them could afford flexible and tough films by solvent casting. The poly(o-hydroxy amide)s exhibited glass-transition temperatures (T-g's) in the range of 141-169 degreesC and could be thermally converted into the corresponding polybenzoxazoles approximately in the region of 240-350 degreesC, as indicated by the DSC thermograms. Flexible and tough films of polybenzoxazoles could be obtained by thermal cyclodehydration of the poly(o-hydroxy amide) films. All the polybenzoxazoles were amorphous and showed an enhanced T-g but a dramatically decreased solubility as compared with their poly(o-hydroxy amide) precursors. They exhibited T-g's of 215-272 degreesC by DSC and showed insignificant weight loss before 500 degreesC in nitrogen or air.