Diphyllobothrium spp., also known as fish tapeworms, is the largest human tapeworm, reaching up to 25 meters of length. Human are considered the definitive host in the Diphyllobothrium lifecycle. Adult tapeworms attach to human intestinal mucosa with to bilateral grooves. There are at least 14 different species of Diphyllobothrium spp. Capable of causing Dyphyllobothriosis, being D. latum and D. nihonkaiense the most frequent etiologic agents in humans. We present the clinical picture and endoscopic images on a patient with incidental finding of Dyphyllobothriosis in a colonoscopy.