The in vitro hydrolysis of a series of copoly(ester amide)s abbreviated as PVGAn, prepared previously by random copolymerization of 1-amino-1-deoxy-2,3,4-tri-O-methyl-5-O-[(pentachlorophenoxy)-succinyl]-L-arabinitol hydrochloride and 5-amino-1-O-[(pentachlorophenoxy)glutaryl]pentanol hydrochloride, has been performed in phosphate buffer at 37 degreesC and evaluated by weight loss and intrinsic viscosity. The copoly(ester amide) PVGA46, containing about 50% of the sugar-based monomer, was water-soluble. Its solubility in water displayed a temperature dependence that was studied and related with the hydrolysis process. The degradation of the aliphatic copoly(ester amide) was greatly enhanced with increasing amount of arabinose-succinyl monomer incorporated in the polymer chain. The presence of small amounts of this monomer was enough to produce a noticeable increase in polymer degradability. Spectroscopic investigations of the hydrolysis products provided evidence for succinimide ring formation, supporting the general mechanism proposed for the hydrolysis of poly(ester amide)s containing four-carbon diacid units in their structure.