A series of poly(ester-amide)s based on an ester group containing lithocholic acid derivative [3-(3-car-boxypropionyl) lithocholic acid] and several aromatic diamines (naphthalene-1,5-diamine, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl-sulfone, benzidine, m-phenylenediamine, p-phenylenediamine, and tetraphenylthiophene diamine) was synthesized and characterized by solubility, viscosity, IR, differential scanning calorimetry, thermogravimetric analysis, and optical microscopy. The polymers were soluble in most of the organic solvents and had inherent viscosities in the range of 0.21-0.38 dL/g. All the polymers exhibited a nematic me sophase, but only on shearing. Thermal transitions due to mesophase formation were not seen in the differential scanning calorimetry thermograms. However, the liquid crystalline character of the polymers was observed under an optical microscope. Thermogravimetric analyses revealed the maximum decomposition temperature was 390-435°C for these polymers. © 2006 Wiley Periodicals, Inc.