Only seven cases of osteoma arising in the middle turbinate have been reported to date. We report the eighth case, involving osteoma in the middle turbinate of a child. This young boy was initially examined at the age of nine for the main complaint of nasal obstruction. Although a large osteoma with a maximum diameter of 30 mm was observed on computed tomography (CT), the patient was only observed because of the wishes of the family. At 13 years, he was again examined, as a result of worsening of the nasal obstruction. CT revealed that the osteoma had enlarged to a maximum diameter of 41 mm. Endoscopic surgery was attempted, but because of difficulties, the osteoma instead had to be removed under direct vision via a gingival incision. The final pathological diagnosis was osteoid osteoma. The nasal obstruction disappeared following surgery, with no recurrence after more than 12 months postoperatively.