Ameloblastoma is the most common clinically significant epithelial odontogenic tumor, and is considered a benign but locally aggressive tumor of the craniofacial region. We present the case history of a 46-year-old male patient who had a nasopharyngeal carcinoma (NPC) treated by irradiation, which was complicated by the occurrence of an ameloblastoma. Following a review of the English language literature, this case history was identified as being the first report, to our knowledge, of the occurrence of ameloblastoma in a patient who had been irradiated for an NPC. This case report highlights the importance of regular dental care for a patient who had an NPC and was treated with radiation therapy.