The ectoparasitic protozoan fauna resident on farmed and wild common carp (Cyprinus carpio L., 1758) from two localities in the Sinop region of Turkey were investigated during the period June 1994–May 1995. Following the investigation of 125 common carp, Trichodina acuta Lom, 1961, Trichodina mutabilis Kazubski and Migala, 1968, Trichodina nigra Lom, 1960, Trichodinella subtilis Lom, 1959, Apiosoma piscicola Blanchard, 1885 and one Epistylis species were identified. The prevalence (%) and mean intensity levels of the parasites found were recorded monthly and in different fish length groups of common carp. Trichodina mutabilis, Trichodinella subtilis and Apiosoma piscicola represent new parasite records for Turkey, with Trichodina acuta being tentatively suggested as a new parasite record. © 1998 Taylor & Francis Group, LLC.