Ameloblastic fibrodentinoma (AFD) is classified as a rarely seen benign mixed odontogenic tumor. Ameloblastic fibrodentinoma is common in children and young adults with painless swelling and mostly seen at the mandibular posterior region and usually associated with unerupted tooth. In this clinical report, an 11-year-old-boy referred to Ankara University, Faculty of Dentistry, with the complaint of pain and swelling at the mandibular posterior region, diagnosed as AFD, is presented. Extraoral examination showed swelling at the affected side. In intraoral examination, a rough painful swelling was invincible with a delayed eruption of deciduous second molar tooth. Panoramic radiography revealed well-defined radiolucency with large radiopacity above the crown of unerupted permanent second molar in the left mandible. The provisional diagnosis was complex odontoma. Biopsy resulted as AFD. The treatment achieved with total excision of the tumor and the second premolar tooth. Resorbable fixation plates were used for strengthening the excised region of the mandible. No recurrence or clinical complaints were noted during 1-year follow-up.