The present study focused on parasites that infected the blue crab Portunus pelagicus. This crab is a very popular sea food for the inhabitants of the costal sea of Egypt. Samples were seasonally collected from Mediterranean Sea, Ras El Bar, Damietta, Egypt. The present study exhibited that 2 parasitic species (protozoa and larval nematode) infested the crab. The infestation rate varied according to the infected tissue of the host, seasons and sexes. Gills were found to be higher infected ( %) than gonads. Seasonal variation in the parasitic infection showed that the highest prevalence was during winter (37%) and summer (35%). Sex of the host crab also affected the infestation with the parasites. Male crabs were found to be higher infected (78%) than females (22%). So, the current study provides a contribution to our knowledge of the parasites that infesting one of the most important economic sea foods.