Based on published and unpublished material the present study is the first comprehensive work covering all scale worms (Aphroditoidea) currently known to occur in the Mediterranean Sea. In total 66 species representing 38 genera are confirmed, described, shown in detail and taxonomical problems discussed. The aphroditoidean fauna of the Mediterranean Sea comprises the following confirmed number of species: 41 Polynoidae, 11 Sigalionidae, 5 Aphroditidae, 5 Acoetidae, 2 Eulepethidae, and 2 Pholoidae. Identification keys to all species occurring in the Mediterranean and to those of the East Atlantic and the northern part of the Read Sea are provided. In the course of this study three new species, i. e. Harmothoe bellani Barnich & Fiege, 200, Malmgreniella polypapillata Barnich & Fiege, 2001, Eunoe tuerkayi n. sp., and a new genus, Neolagisca Barnich & Fiege, 200 are described and 17 new records of species formerly known from the Atlantic and the Red Sea are reported. Together these two groups represent 30.3 % of the species present. The aphroditoidean fauna of the Mediterranean is closely related to the Eastern Atlantic fauna with 56 common species (84.8 %). Four species (6.1%) also occur in the Red Sea with two of them being likely Lessepsian migrants, representing the first recorded among scale worms. Only six species (9.1%) of Aproditoidea have to be considered endemic to the Mediterranean for the time being, thus representing a much lower number than those reported for many other taxa.weiterlesen