Poly (arylene ether ketone) s containing imide units were prepared by the aromatic nucleophilic displacement reaction of the potassium salts of bisphenols with bis(4-fluorobenzoyl)phthalimides in N-methyl-2-pyrrolidone at elevated temperature. The polymers having inherent viscosities of 0.34-0.77 dL/g were obtained in 2 h. The polymers exhibited glass transition temperatures ranging from 216 to 268-degrees-C and decomposition temperatures (5% weight loss under air atmosphere) ranging from 450-570-degrees-C mainly depending on the bisphenols used in the polymer synthesis. The isothermal TGA measurements (400-degrees-C under air or nitrogen atmosphere) revealed that the 4,4’-biphenol- and hydroquinone-based poly (arylene ether ketone imide) s belong to a superior class of heat resistant polymers. The mechanical properties of these polymers are also described.