An overview around the systematics, biology and ecology of the species so far included in the genus Anisakis is here reported. Immunopathological features related to the clinic forms of human anisakiasis due to the zoonotic species (i.e., A. simplex (s.s.) and A. pegreffii ) as well its diagnosis, are summarized. The epidemiology of anisakiasis, whose incidence is particularly high in those countries having raw fish consumption habits, is reviewed.