Abstract.In a parasitic survey of wild and cultured sea bass,Dicentrarchus labrax(L.), thirteen protozoan species were found. Ectoparasites included two ciliates (Trichodinaspp.), one dinoflagellate (Amylodiniumsp.) and one zooflagellate (Cryptobiasp.). Endoparasites were represented by members of Apicomplexa (Hemogregarinasp.,Eimeriaspp.). Microsporea (unidentified species) and Myxosporea (Myxobilatussp.,Ceratomyxaspp.,Sphaerospora dicentrarchi, Sphaerospora testicularis). Myxobilatussp.,Eimeriaspp. and the microsporean were exclusively found in wild fish, whereasAmyloodiniumsp. andHemogregarinasp. were only detected in cultured fish. Data on prevalence and intensity of infections and on the location in the host are provided. The potential importance of protozoan parasites for sea bass culture is discussed.