Five novel polyamides incorporating phosphine oxide groups have been synthesized by the condensation reaction of bis(4-carboxyphenyl)phenylphosphine oxide with a series of aromatic diamines. The thermal properties of these polymers were investigated by differential scanning calorimetry and thermogravimetric analysis. Glass transition temperatures in the 225-254 degrees C range were recorded, together with good thermooxidative stability (5% weight loss occurring al >420 degrees C) and high char yield upon prolonged heating at 650-800 degrees C (24-50%). Also, good solubility in aprotic polar solvents was observed for all polyamides synthesized.