The aim of this study was to present an endoscopic-assisted intraoral surgical technique for sinus floor augmentation and removal of an antral pseudocyst simultaneously. The patient underwent sinus floor augmentation combined with removal of an antral pseudocyst in the ipsilateral maxillary sinus. Transoral endoscopic technique was applied to check the status of sinus mucosa during the operation. Complications were evaluated. Perforation of the sinus membrane was observed during augmentation procedure, and was covered with an absorbable membrane. No leakage of bone grafts was verified by the endoscope. The patient recovered uneventfully and final dental implants were inserted successfully. Therefore, sinus floor augmentation and removal of the maxillary sinus pseudocyst can be fulfilled at the same time, to reduce the time before dental rehabilitation. Transoral endoscopic technique can be of great helpful to the treatment of maxillary sinus diseases and sinus floor augmentation, owing to minimal invasion and optimal visualization.