This report is the seventh iteration of the biennial listing of a consensus of the 25 primate species considered to be among the most endangered worldwide and the most in need of conservation measures. The list includes 5 species from Africa, 6 from Madagascar, 9 from Asia, and 5 from the Neotropics. This publication includes comprehensive information about the threats facing these primates, with bibliographic references cited in the text. The species profiles from the 2008-2010 edition have been updated for those species remaining on the list, and additional profiles for newly listed species have been added.