A 2-year-old infant was admitted to our hospital on Sept. 25, 1967 with chief complaints of bloody profuse mucopurulent nasal discharge on left side and slight night sweating intermittently for about 18 months duration. Physical examination revealed marked congestion on nasal mucosa and bloody profuse mucopurulent secretion in left nasal cavity. A piece of bone was extracted on left upper premolar tooth area with forceps and oroantral fistula was demonstrated. Roentgenologic study of the PNS showed homogenous opacity on left maxillary sinus and irregular radiolucent defect seen in the zygoma adjacent of the lateral wall of the left maxillary sinus extending into the alveolar region. On 3rd day of admission, Caldwell-Luc operation with closure of oroantral fistula were performed under general anesthesia. Postoperative course was uneventful.