A new record of a rare deep-water scorpionfish Ectreposebastes niger (Fourmanoir, 1971), is described from the south-western Indian Ocean. This is the ninth record in the Indian Ocean and the first documented record of this species in the waters of Reunion Island. It is also the first record of this species in the Indian Ocean since 1982. Its congener, Ectreposebastes imus Garman, 1899 is more common: together with non-published records from museums and online databases the number of verified Indian Ocean records exceeds 15 individuals. Both species are pseudo-oceanic, usually associated with continental and peri-insular slopes and seamounts between 200 and 1300 m depth, occupying a wide range of habitats from demersal to pelagic in the meso- and bathypelagic zones.