Ameloblastic carcinoma is a rare type of odontogenic tumor. We report a case of peripheral ameloblastic carcinoma occurring in the maxilla. A 73-year-old man was referred to our hospital because of a mass of the right maxillary gingiva. Biopsy yielded a diagnosis of ameloblastic carcinoma, and partial resection of the maxilla was performed. Invasion into the bone was not observed in the excised specimen, and peripheral ameloblastic carcinoma was diagnosed. About one and a half years after the operation, there were no symptoms of recurrence. However, there are cases in which local relapse occurs several years later, and long-term observation is necessary.