Amino-functionalized poly(arylene ether ketone)s have been synthesized by nucleophilic aromatic substitution from isomeric amino-functionalized monomers and Bisphenol A. The polymerizations have been found to proceed without any side reactions. The polymers were characterized by IR, H-1 NMR, and C-13 NMR spectroscopy and gel permeation chromatography. The glass transition temperatures and thermal stabilities of the isomeric polymers have been determined by differential scanning calorimetry and thermogravimetry. A strong dependence of the glass transition temperature on the position of the amino function in the polymer backbone was observed. This could be explained by inter- or intramolecular hydrogen bonding. Owing to the good reactivity of the amine groups, those polymers will then allow further modifications and easily lead, for example, to amide formation or to the grafting of various molecules.