OBJECTIVE This study aimed to describe the technique and clinical outcomes of using a palatal mucoperiosteal flap for oro-nasal fistula closure following resection of maxillary sinus cancer. METHODS The study was conducted with the permission of the internal review board of the Japanese Red Cross Wakayama Medical Center. Five consecutive cases from 2016 to 2020 of surgically treated maxillary sinus cancer in which the oro-nasal fistulas were closed using a palatal mucoperiosteal flap were retrospectively reviewed. RESULTS Following tumor resection, the oro-nasal fistula was closed using a palatal mucoperiosteal flap. Complete separation of the oral and nasal cavities was achieved in four patients. Oral intake was resumed within two weeks in four patients. All the patients were able to eat foods similar to those in the preoperative period. Their postoperative speech function was excellent, with no difficulty in communicating with others. CONCLUSIONS In the selected cases of maxillary sinus cancer, preservation of the palatal mucosa and closure of an oro-nasal fistula using a palatal mucoperiosteal flap was possible with reasonable outcomes for swallowing and speech functions. The use of this local flap is recommended as a minimally invasive procedure that can be performed especially in patients with limited physiological reserves which preclude free flap reconstruction.