In the years 1994-1996, a total of 592 specimens of herring Clupea harengus membras L., caught in southern Baltic, were examined. The investigations revealed four species of trematodes: Hemiurus luhei, H. raabei, H. levinseni, Brachyphallus crenatus, two species of nematodes: Hysterothylacium auctum (syn. H. aduncum), and Anisakis simplex and three acanthocephalans: Echinorhynchus gadi, Metechinorhynchus salmonis and Pomphorhynchus sp. The finding of H. levinseni constitutes the first record of this species in Polish waters. The infection parameters of herring (prevalence, intensity and abundance) were compared in relation to different capture areas and seasons of the year. Possible affects of the feeding ground, fish body length and the spawning group of herring on the infection levels were also examined. No relation was observed between the place and the season of catch and the infection level of herring. The fish representing different feeding grounds (Baltic, Danish Straits) and sequential length classes showed variable parameters of infection.