3,3-Bis[4-(4-aminophenoxy)phenyl]phthalimidine (2) was used as the monomer with various aromatic dicarboxylic acids and tetracarboxylic dianhydrides to synthesize polyamides and polyimides, respectively. The diamine 2 was derived by a nucleophilic substitution of 3,3-bis(4-hydroxyphenyl)phthalimidine with p-chloronitrobenzene in the presence of K2CO3 and then reduced by hydrazine and catalyst. Polyamides (4a-g) having inherent viscosities of 0.94-2.08 dlg(-1) were prepared by direct polycondensation of the diamine 2 with various aromatic diacids using triphenyl phosphite and pyridine as condensing agents. All the aromatic polyamides were amorphous and readily soluble in various polar solvents such as N,N-dimethylacetamide (DMAc), N,N-dimethylformamide, dimethylsulfoxide and N-methyl-2-pyrrolidone (NMP). Transparent and flexible films of these polymers could be cast from the DMAc solutions. These aromatic polyamides had glass transition temperatures in the range of 307-338 degrees C and 10% weight loss occurred up to 460 degrees C. The polyimides were synthesized from diamine 2 and various aromatic dianhydrides via a two-stage procedure that included ring-opening polyaddition in DMAc to give poly(amic acid)s, followed by thermal or chemical conversion to polyimides. Most of the aromatic polyimides obtained by chemical cyclization were found to be soluble in NMP, m-cresol and o-chlorophenol. These polyimides showed almost no weight loss up to 500 degrees C in air or nitrogen atmosphere.