The Roseobacter group within the family Rhodobacteraceae consists of nearly 70 genera and app. 180 species. They thrive in a broad variety of marine habitats and were found free-living in seawater, associated with micro and macro algae, marine sponges and invertebrates as well as in biofilms, sea ice and sediments. n the present study, we describe the abundance, distribution and diversity of the Roseobacter group in rather oligotrophic deep-sea sediments derived from the Pacific Ocean as all other benthic studies were performed on relatively eutrophic coastal sites or high-energy systems.