The aim of this study was to investigate parasites fauna of Neogobius pallasi in the southern part of the Caspian Sea. A total of 738 specimens of N. pallasi were collected from four stations, Anzali (238 specimens), Nowshahr (177 specimens), Babolsar (160 specimens) and Amirabad (163 specimens) using hand trawl net. During this study, four nematode species were identified, Raphidascaris acus, Eustrongylides excisus, Streptocara sp. and Contracaecum sp. There were not observed specimens from other groups of parasites. The highest prevalence was observed in R. acus (33%) and the lowest in Contracaecum sp. with the prevalence of less than 1%. Among the specimens of different stations, infection parameters were significantly higher in Anzali specimens. Probably, differences in abundance and distribution of intermediate and final hosts were the reason of this dissimilarity.