The book presents 190 known species of the genus Ataenius HAROLD, 1867, inhabiting American continent and adjacent archipelagos. The essential diagnoses of species inluding their known and new synonymy, affinities, bionomy and distribution are associated with 26 plates of colour pictures and 12 plates of greyscale drawings of the male genitalia and other morphological details. The literature includes revisions, monographs and all publications on taxonomy and biology of the genus.