In this manuscript, we present a rare case report of giant complex odontoma in the maxillary sinus, where the applied therapy included complete excision of the lesion with a conservative approach. Odontomas are also called benign growth abnormalities or hamartomas. They represent a more common type of odontogenic tumor and are related to various disorders such as bad dental placements, expansion, increased volumetric bone, and no eruption of permanent teeth. Usually they have an asymptomatic evolutionary course. The etiologic factors, although obscure, are related to local trauma, infection, and genetic factor. The structural composition of an odontoma consists of mature dental tissues. Odontomas can be differentiated according to their anatomical presentations: Compound odontoma-clusters of several denticles and complex odontoma-well defined tumefaction mass. The diagnosis can be performed by radiographic examination.