An anaerobic, halorespiring bacterium (strain PCE-M2(T) = DSM 13726(T) = ATCC BAA-583(T)) able to reduce tetrachloroethene to cis-dichloroethene was isolated from an anaerobic soil polluted with chlorinated aliphatic compounds. The isolate is assigned to the genus Sulfurospirillum as a novel species, Sulfurospirillum halorespirans sp. nov. Furthermore, on the basis of all available data, a related organism, Dehalospirillum multivorans DSM 12446(T), is reclassified to the genus Sulfurospirillum as Sulfurospirillum multivorans comb. nov.