Ameloblastic fibroma is a benign tumor of mixed odontogenic origin, which occurs in ages from 12 to 15 years, frequently in the molar area. Generally it is asymptomatic, however the biggest lesions can be associated to pain and swelling. Using X-ray they appear well defined, transparent, with a sclerotic radio-opaque border; occasionally they can simulate a dentigerous cyst. The treatment is generally conservative. This report describes an ameloblastic fibroma in a 14-year-old male, which involved the three right molars and both the ascending ramous and the coronoid process, which was treated conservatively with the extraction of the affected teeth, tumor extirpation and osseous curettage.