A new species of ophiuroid, Amphioplus (Amphioplus) hexabrachiatus, is described from southwest of Iceland at a depth of 1000-1500 m, collected by the Benthic Invertebrates of Icelandic Waters (BIOICE) programme. The species is hexamerous, reproduces asexually by division, and reaches a maximum size of about 2.5 mm disc diameter. This is the first six-armed species of Amphioplus and the third species of the genus known from the North Atlantic. It is found at temperatures of 3-5°C, probably restricted in its geographical distribution by surrounding colder water areas.