Organohalide respiring bacteria (OHRB) are pivotal to degradation of halogenated pollutants in a large variety of anaerobic ecosystems, and hence are key players in the remediation of the large volumes of subsurface soils, groundwater, as well as sediments in freshwater- and marine environments. As these environmental pollutants are among the most abundant priority pollutants, and thus pose a continuing threat to human and environmental health and integrity, a better understanding of eco-physiology and adaptability of reductively dehalogenating populations is setting the stage for their further exploitation as dedicated degraders in biological remediation processes. Moreover, OHRB have an important role in global biogeochemical halogen cycling, and unlock polyhalogenated compounds for complete mineralization, hence contributing to refueling the carbon cycle. While genome sequences are now available or in production for several isolates within the Chloroflexi (Dehalococcoides, Dehalobium) and d-Proteobacteria (Anaeromyxobacter, Geobacter lovleyi), only limited efforts have been undertaken to elucidate genomes of halorespiring bacteria belonging to the Firmicutes, namely Dehalobacter and Desulfitobacterium spp. The availability of more genomes from this unique group of organisms will enable us to link sequence information with current knowledge about their physiology and to gain insight into their evolution.