The present report describes a case of gossypiboma in the maxillary sinus after treatment for the fracture of the orbital floor with review of the literatures on this interesting disease entity. The suspicion of gossypiboma should be raised when a patient with a history of previous sinonasal surgery, especially Caldwell-Luc approach, presents with chronic recurrent or refractory sinusitis. Because of the rarity of reported cases, typical computed tomography findings of gossypiboma in the sinonasal area have not been established. In the present case, because the gauze was retained for 25 years in the maxillary sinus, computed tomography findings revealed nonspecific findings. Because a foreign body left behind after operation may lead to a serious medicolegal issue, it is worth reemphasizing that the best general approach to retained surgical foreign body is to prevent its occurrence.