Background. Ectopic eruption of supernumerary teeth in the nasal cavity is extremely rare, and most cases usually involve the maxillary sinus or are accompanied by dental cysts. It is usually discovered during adulthood. Case. A 5-year-old patient presented with an intranasal mass and intermittent nasal bleeding that lasted for 1 year. He was taking medication for symptoms of allergic rhinitis, such as nasal obstruction and intermittent epistaxis, without any endoscopic evaluation for 1 year. On nasal endoscopy, a needlelike whitish mass was observed on the left nasal floor. On paranasal sinus computed tomography, it appeared as a pointed highdensity mass covered by soft tissue. The intranasal mass which was a supernumerary tooth was completely removed using a pediatric endoscope. Conclusions. Detection of supernumerary teeth in the nasal cavity of children without symptoms is difficult, and it can be delayed; although the child, in this case, had nonspecific nasal symptoms, supernumerary teeth was not considered in the diagnosis. This case report raises awareness and provides evidence for the clinical characterization and optimal treatment of supernumerary teeth in children.