This fully illustrated guide is designed to assist with the identification of a selection of deep-sea cartilaginous fishes of the Southeastern Atlantic Ocean and that portion of Southwestern Indian Ocean from 18°42'E to 30°00'E (FAO Fishing Area 47), that are of major, moderate or minor importance to fisheries. In this region, the deep-sea chondrichthyan fauna is currently represented by 50 shark, 20 batoid and 8 chimaera species. Identification Guide to the Deep-Sea Cartilaginous Fishes of the Southeastern Atlantic Ocean includes full species accounts for 37 shark, 9 batoid and 4 chimaera species selected as being the more difficult to identify and/or commonly caught. Each species is described, depicted with a colour illustration and photo, and key distinguishing features of similar–looking species occurring in the same area are highlighted allowing for easy and accurate identification in the field. Keys to the shark and batoid orders and families, together with keys to chimaera and skate genera are also provided. Identification Guide to the Deep-Sea Cartilaginous Fishes of the Southeastern Atlantic Ocean is intended to help fishery workers collecting catch data in the field in the identification of the cartilaginous fish species they might encounter. It is conceived to be updatable, offering the possibility to add new species accounts as new species are described.