Aromatic polyamides were prepared by an AlCl3 or HCl-catalyzed polymerization of toluene diisocyanate or methylenebis(phenyl isocyanate) with adipic acid at low temperatures (less than or equal to 100 degrees C) in a short reaction time (3-4 h). The intrinsic viscosity of the polymers was approximately 1.1 dL/g as determined at 25 degrees C with m-cresol as solvent. indicating that the polyamides obtained by this method have relatively high molecular weights. The polymers exhibit high glass transition temperatures and good thermal stability.