Ameloblastic carcinoma, a rare ma1ignant odontogenic tumor, is a highly aggressive tumor with rapid growth and a high potential for distant metastasis. Surgical resection is the most common treatment modality, while there are stil1 controversies about the efficacy of neck dissection, radiotherapy, and chemotherapy. Herein we report a case of ameloblastoma with malignant change in the right maxilla of a 25-year-old male patient. The patient had had an ameloblastoma in the right maxi\la 2 years previous, which was surgically removed. Two years later, a tumor recurred in the right maxil1ary sinus, and was surgical1y excised again. The histological examination revealed that the tumor consisted of 2 distinct portions. The major part of the tumor was a typical ameloblastoma. However, a smal1 portion of the tumor revealed an ameloblastic carcinoma. The patient received adjuvant radiotherapy after the operation. There was no evidence of recurrence or distant metastasis 2.5 years after the second surgery.