Ameloblastoma is the most common odontogenic tumor of the mandible with rare occurrence in the maxilla. The present report is concerned with rare maxillary ameloblastoma observed in a 43-year-old male patient at St. Mary's Hospital. The patient has had swelling and mass in the right cheek and gingivolabial fold of one and one half years' standing. Physical examination revealed a hard palpable mass in the right cheek and gingivolabial fold areas with hypertrophied middle turbinate and left side deviation of the septum. Roentgenologic study showed diffuse clouding of the right maxillary sinus and irregular bony destruction was noted in the lower part of the sinus. The nasal cavity was completely obstructed by a spaceoccupying lesion. A biopsy specimen secured from the right maxillary sinus was studied histologically and ameloblastoma was diagnosed.