Leech infestation is a very rare phenomenon in humans. It mostly occurs in humans when rural untreated water is drunk or while swimming in streams or lakes. When leeches adhere to the mucous membrane, they ingest blood. Thus, they can sometimes cause severe anemia that may require blood transfusion. We report a case that was referred to emergency service with bleeding in the floor of the mouth. A 10-year-old child was referred to the emergency service of a city hospital with a complaint of swelling in the floor of the mouth and spitting of blood. The patient was promptly taken to the operating room. Using local anesthesia, a surgical incision was made, and a moving, dark brown foreign body was removed from the floor of the mouth and identified as a leech. Leech endoparasitism should be considered as a cause of unexplained anemia due to bleeding from the throat. Accordingly, leech infestation must be considered in differential diagnosis when a patient complains of spitting of blood, hoarseness, or dysphagia.