The effect of lead (Pb) toxicity on bone mineralization was investigated in a wild population of red-legged partridge (Alectoris rufa) inhabiting a farmland area contaminated with Pb-shot from recreational hunting activities in Albacete, a southeastern province of Spain. Femora from 40 specimens of red-legged partridge were analyzed for Pb by graphite furnace atomic absorption spectroscopy (GF-AAS), and for bone composition by Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). The FTIR and DRX data of bone were analyzed in detail to determine possible alterations in bone mineral chemistry and crystallinity due to Pb toxicity. Results showed a marked decrease in the degree of mineralization as Pb concentrations in bone tissue increased while XRD analyses showed that the crystallinity of apatite crystals increased with the Pb load in bone. These load-dependent effects are indicative that Pb contamination altered bone remodeling by reducing new bone mineral formation and demonstrate that bone quality is a sensitive indicator of adverse effects on wild bird populations exposed to Pb pollution. ; This work was supported by Research Projects of the Spanish government: CTM2007-65713, CGL2011-25906, GREIB.PYR-2010-01 and the Junta de Andalucía (research group RNM-179 and project P08-RNM-4169). Currently, MMH benefits from a Marie Curie Intra-European Fellowship for Career Development (PIEF-GA-2011-299747) within the 7th Framework Programme (FP7 2007-2013) of the European Commission. ; Peer Reviewed