Seven dolphins (Delphinus sp.) that were found stranded near Point Mugu, California between 1966 and 1970 were given complete necropsy examinations. In all seven cases a similar pathological picture was observed. The findings included adult trematodes in the bile and pancreatic ducts, severe liver damage, and massive brain necrosis due to the presence of numerous trematode ova in the brain tissue. We suggest that the stranding and subsequent death of all seven animals resulted from this disease.