Stereoregular poly(ester amide)s (PEAs) were prepared by the polycondensation method using naturally occurring D-xylose and aromatic diacids as the starting materials. The polymers were characterized by elemental analysis, GPC, IR, and H-1- and C-13 NMR spectroscopies. Thermal and X-ray diffraction studies revealed them to be mainly amorphous. The polymers are hydrophilic and their degradation studies were carried out at 37 and 80 degrees C in buffered salt solution at pH 8. The degradation study was monitored by mass loss, GPC, IR, and NMR spectroscopies. The hydrolytic degradation of these PEAs occurred rapidly by hydrolysis of the ester functions to a final compound, which maintained the amide functions. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4711-4720, 2010