Halanaerobium praevalens Zeikus et al. 1984 is the type species of the genus Halanaerobium, which in turn is the type genus of the family Halanaerobiaceae. The species is of interest because it is able to reduce a variety of nitro-substituted aromatic compounds at a high rate, and because of its ability to degrade organic pollutants. The strain is also of interest because it functions as a hydrolytic bacterium, fermenting complex organic matter and producing intermediary metabolites for other trophic groups such as sulfate-reducing and methanogenic bacteria. It is further reported as being involved in carbon removal in the Great Salt Lake, its source of isolation. This is the first completed genome sequence of a representative of the genus Halanaerobium and the second genome sequence from a type strain of the family Halanaerobiaceae. The 2,309,262 bp long genome with its 2,110 protein-coding and 70 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.