Toxoplasma gondii is a parasitic protozoan species belonging to the Family Sarcocystidae. The life cicle of T.gondii has two phases; a sexual phase, which take placein a definitive host (members of the family Felidae); and an asexual phase, in the intermediate hosts (any warm-blooded animal, including several species of marine mammals). It has been considered a potential cause of mortality in many species of domestic and wild animals, including the cetaceans species. The present study is focused on 85 Atlantic spotted dolphins (Stenella frontalis) stranded along the coast of the Canary Islands, from 2000 to 2013. A complete necropsy was performed on 60 specimens with a very fresh to moderate autolysis conservation status. During necropsy, selected samples were collected and fixed in 10% neutral buffered formalin, routinely processed and stained with hematoxylin and eosin for histopathological studies. Histology revealed the presence of granulomatous inflammation and necrotizing encephalitis associated to tachyzoites and tissue cysts[PMF1] . T. gondii was detected immunohistochemically by using a polyclonal antiserum (anti-T.gondii). As a result, 8 out of 60 (13,3) cetaceans presented T. gondii protozoan. We are conducting further studies to investigate other possible concomitants pathologies in these animals.