OBJECTIVE : The aim of this study was to evaluate the efficacy of simultaneous endoscopic endonasal sinus surgery and sinus augmentation with immediate implant placement. METHODS : The study patients (n = 23) were partially or completely edentulous in the posterior maxilla and required maxillary sinus augmentation. All included patients had a sinus pathology confirmed clinically and radiographically. The technique of simultaneous endoscopic endonasal sinus surgery and sinus augmentation was used in 15 patients, with eight endonasal sinus surgery procedures being performed 2-3 months before sinus augmentation. Where possible, implants were placed during the same surgical procedure (with a ridge bone height of at least 4 mm). RESULTS : There were no any major intraoperative complications. Implants placed in the reconstructed areas were shown to integrate normally, and postoperative occlusal function and aesthetics were favorable. Of the 95 implants placed in these 23 patients, two failed to osseointegrate. CONCLUSIONS : The method of simultaneous endoscopic endonasal sinus surgery and sinus augmentation with immediate implant placement leads to a reduction in postoperative complications, significantly shortening the rehabilitation period for patients with maxillary sinus diseases and insufficient bone tissue.