[Background] Genomic studies of endangered species provide insights into their evolution and demographic history, reveal patterns of genomic erosion that might limit their viability, and offer tools for their effective conservation. The Iberian lynx (Lynx pardinus) is the most endangered felid and a unique example of a species on the brink of extinction. [Results] We generate the first annotated draft of the Iberian lynx genome and carry out genome-based analyses of lynx demography, evolution, and population genetics. We identify a series of severe population bottlenecks in the history of the Iberian lynx that predate its known demographic decline during the 20th century and have greatly impacted its genome evolution. We observe drastically reduced rates of weak-to-strong substitutions associated with GC-biased gene conversion and increased rates of fixation of transposable elements. We also find multiple signatures of genetic erosion in the two remnant Iberian lynx populations, including a high frequency of potentially deleterious variants and substitutions, as well as the lowest genome-wide genetic diversity reported so far in any species. [Conclusions] The genomic features observed in the Iberian lynx genome may hamper short- and long-term viability through reduced fitness and adaptive potential. The knowledge and resources developed in this study will boost the research on felid evolution and conservation genomics and will benefit the ongoing conservation and management of this emblematic species ; The financial support for this work was provided by Banco de Santander, CSIC, and Fundación General CSIC through a “Proyectos Cero” grant. FC and BM-C were hired under the EcoGenes project funded by the European FP7 program (264125-FP7-REGPOT-2010-1) and AVl and FCa under the INB Project PT13/0001/ 0021 (ISCIII - Subdirección General de Evaluación y Fomento de la Investigación/ FEDER “Una Manera de hacer Europa”). EBD-CSIC and CRG received support from the Spanish Ministry of Economy and Competitiveness under the “Centro de Excelencia Severo Ochoa 2013-2017” program, grants SEV-2012-0262 and SEV-2012-0208. We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI). ; Peer Reviewed