Achieving water-induced shape-memory property in poly(D,L-lactide) (PDLLA), generated by means of advanced processing methods, opens possibilities to develop novel bioresorbable medical devices with shape-memory properties activated by the human body without external heat. The main phenomena that affect the molecular movements that enable the water-induced shape-memory effect in an oriented PDLLA in an aqueous environment at physiological temperature are related to the water driven disruption of the intermolecular dipole-dipole and/or hydrogen bonding of the oriented PDLLA chains and the subsequent decrease of the glass transition temperature (T-g) to the range of physiological temperature. The diffused water in the polymer matrix decreased the energy needed to finish the glass transition process explaining the higher shape-recovery rate of the -irradiated PDLLA with respect to the non--irradiated PDLLA in an aqueous environment at physiological temperatures. The water-induced decrease in the T-g was thermally reversible. The efficacy of the generated shape-memory was tested with PDLLA shape-memory nails in a pullout test, in which the pullout force of the PDLLA nails increased 360% during a seven day test period in vitro at 37 degrees C. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4209-4218, 2013