determination of their longevity. In the present work, the use of high-throughput technologies allowed us to determine the plasma lipidomic profile of 11 mammalian species ranging in maximum longevity from 3.5 to 120 years. The non-targeted approach revealed a specie-specific lipidomic profile that accurately predicts the animal longevity. The regression analysis between lipid species and longevity demonstrated that the longer the longevity of a species, the lower is its plasma long-chain free fatty acid (LC-FFA) concentrations, peroxidizability index, and lipid peroxidation-derived products content. The inverse association between longevity and LC-FFA persisted after correction for body mass and phylogenetic interdependence. These results indicate that the lipidomic signature is an optimized feature associated with animal longevity, emerging LC-FFA as a potential biomarker of longevity ; We acknowledge funding from the Spanish Ministry of Science and Innovation (CGL2010-18124) to J.C.A.; from the Spanish Ministry of Health (PI11-01532) to M.P.O.; and from the Spanish Ministry of Science and Innovation (BFU2009-11879/BFI), the Generalitat of Catalonia (2009SGR735), and the La MaratoTV3 Foundation to R.P. R.C. was supported by a Generalitat of Catalonia Predoctoral Fellowship. We thank David Argiles for excellent technical assistance. We thank Dr. Montserrat Rué for her support in statistical analyses.