A taxonomic list of new records of polychaete worms collected off the coasts of the state of Campeche, Mexico, is reported. Distinctive taxonomic characters are included for each species, as well as information on their geographical distribution. The following species were reported for the first time in the study area: Mediomastus ambiseta (Hartman, 1947), Rasghua lobatus (Hartman, 1947), Eunice stigmatura (Verrill, 1900), Eunice unifrons (Verrill, 1900), Marphysa brevitentaculata Treadwell, 1921, Marphysa orensanzi Carrera-Parra and Salazar-Vallejo, 1998, Notaulax midoculi (Hoagland, 1919), Glycera pacifica Kinberg, 1865, Lumbrineris erecta Moore, 1904, Perinereis mochimaensis Linero, 1983, Platynereis dumerilii (Audouin and Milne-Edwars, 1834), Naineris dendritica (Kinberg, 1867), Pectinaria gouldii (Verrill, 1874). Branchiomma bairdi (McIntosh, 1885) and Ficopomatus miamiensis (Treadwell, 1934) are reported as alien species, while Pseudopolydora floridensis Delgado-Blas, 2008 is recorded for the first time in Mexico. (C) 2016 Universidad Nacional Autonoma de Mexico, Instituto de Biologia. This is an open access article under the CC BY-NC-ND license.