Oroantral communication is an unnatural communication of the maxillary sinus with the oral cavity, often resulting from dental extractions, infection, trauma, or excision of cysts or tumors. Pathological epithelialization of oroantral communication leads to oroantral fistula. Various techniques have been proposed for surgical closure. Uneventful healing of the defect can be achieved in the absence of antral infection. Hence, medical management of maxillary sinusitis should precede surgical closure of the defect. Here, we report a case of an oroantral fistula of the left maxillary third molar, caused by a secondary infection of the extraction site, managed primarily by antibiotics, topical steroids, and irrigating agents followed by surgical closure. It is essential to carefully inspect the post-extraction socket of maxillary teeth due to its high risk of development of oroantral communication. Also, the management of oroantral communications needs early detection to prevent infection and to prevent transforming into an oroantral fistula. In case of an infected oroantral communication or fistula, priority rests on treating the infection first and followed by surgical repair.