The parasitic copepod fauna of 182 specimens of Mustelus schmitti Springer from the coast of Mar del Plata, Argentina was investigated. Three species of parasitic copepods were identified: Nessipus orientalis Heller, 1865 from the buccal cavity, Perissopus oblongus (Wilson, 1908) from the edge of pectoral, pelvic, dorsal, anal and caudal fins and in claspers, and Lernaeopoda galei К rayer, 1837 from the base of the pectoral fins. N. orientalis was most common being present the entire year, while P. oblongus and L. galei occurred seasonally with low prevalence and mean intensity. There were differences in the site of infection by these copepods and variations in the relationship between prevalence and mean intensity and host size and seasonality. These parameters were unrelated to host sex. Our data suggest that the structure of this parasite community is a result of a complex of biotic and abiotic factors, such as temperature, spawning and breeding preferences of the host, and overlapping in the distribution of different shark species. This is the first report of N. orientalis in Argentinean waters.