Among the benthic lithological samples collected during the Spanish Antarctic survey GEBRAP 1996–97 in the Bransfield Strait, two new oweniid (Annelida, Polychaeta, Oweniidae) species were collected: Myriochele riojai n. sp. and Myriochele robusta n. sp. Myriochele riojai is closely related to M. heeri Malmgren, 1867 but differs in body size, number and distribution of the notosetae and in the position of elongated abdominal body segments. Myriochele robusta differs from all known species of the genus owing to its possession of a biramous setiger between two uniramous setigers in the anterior (thoracic) body region. A key to oweniid species recorded in Antarctic waters is provided.