A new method for the preparation of poly(ester amide)s derived from glycolic acid units has been developed. Glycolic acid units can be incorporated with a high yield into a nylon-n or a nylon-n,m. The synthesis is based on a final thermal polycondensation with the formation of a metal halide salt as a driving force. New poly(ester amide)s have high molecular weights, good mechanical behaviour, and variable thermal properties, giving rise to a group of materials with potential interest as biodegradable materials in applications like surgical sutures.