"The Mexican Barcode of Life (MEXBOL) project started as an initiative by researchers who wanted México to join the international DNA barcoding (iBOL) collaboration to establish a genetic system of species identification and discovery. MEXBOL has three main nodes associated with different research institutions in the northern, central, and southern parts of the country. At the beginning of 2009, the laboratories of the three nodes began to operate with support from the University of Guelph in Canada where DNA barcoding began in 2003. By the end of 2011, the laboratories in México will be completely equipped and fully operational. The project is funded by the Consejo Nacional de Ciencia y Tecnología (CONACyT). In addition, the steering committee of MEXBOL supports the Comisión Nacional para el Conocimiento y Uso de la Biodiversidad (CONABIO) initiative to offer grants to any university and research center for barcoding collections of Mexican specimens. We present preliminary results of projects dealing with barcoding Mexican mammals. The aims of these analyses are to evaluate the importance of the DNA barcoding (using cytochrome c oxidase subunit I gene; COI) for the identification of species, study of genetic diversity, and taxonomic review. Our preliminary data suggest that DNA barcodes can be used for the discovery of cryptic species and have important implications to the understanding of the mega-diversity of mammals in México."