Book excerpt: Microbial reductive dehalogenation mediated by organohalide-respiring bacteria plays a critical role in the natural halogen cycle, representing a promising solution for removal of organohalide pollutants. This Research Topic presents many of the more recent advances that have been made in this area. Authors from leading research groups contributed to this eBook, and provided mechanistic insights into organohalide respiration, as well as their bioremediation implications, at molecular, cellular, community and system levels.