The microhardness of a series of biodegradable polyesters was determined. The nanostructural features of these materials were studied by wide-angle X-ray scattering (WAXS), small-angle X-ray scattering (SAXS), and differential scanning calorimetry. Analysis of the SAXS and WAXS patterns allowed direct derivation of the degree of crystallinity and crystal thickness values, and correlations of the micromechanical properties are presented. The differences in the thermal and mechanical properties exhibited by the studied systems and the ones found in other aromatic polyesters are explained as due to the different chemical natures of the monomeric units. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 2591-2596, 2010