Book excerpt: The International Guidelines for the Management of Deep-sea Fisheries in the High Seas (DSF Guidelines) were adopted by FAO in 2008. [Author] The first and only review of the implementation of the Guidelines took place in 2010. [Author] There have been many advances in implementation since then and it is timely to conduct another review. [Author] The DSF Guidelines have been used to guide regional fisheries management organizations and states in the development of spatial management processes defining fishing grounds and protecting vulnerable marine ecosystems. [Author] The DSF Guidelines also require that harvested fish stocks and impacts on bycatch species are assessed and managed, but this has been less well implemented. [Author]