BACKGROUND: Transoral incisionless fundoplication (TIF) with the Medigus ultrasonic surgical endostapler (MUSE) is a new intervention for the treatment of the gastroesophageal reflux disease (GERD). The aim of this study was to assess the 12-month clinical, functional, and endoscopic effects of TIF by MUSE. METHODS: Patients undergoing MUSE completed the GERD-Health Related Quality of Life (GERD-HRQL) and Reflux Symptom Index (RSI) questionnaires, and underwent endoscopy, esophageal 24-hour pH-impedance recording, and high resolution manometry (HRM) before the TIF procedure and 12 months later, or after 6 months for HRM. RESULTS: Among the 37 patients treated, esophageal intubation was not possible in one and esophageal perforation occurred in another. Clinical and endoscopic follow-up at 12 months was completed in 20 patients, with significant improvements in GERD-HRQL, RSI, heartburn, regurgitation scores, and proton pump inhibitor (PPI) consumption observed. One patient required surgery for persisting symptoms. Functional follow-up was possible in 13 patients and showed no significant improvements in the analyzed parameters. CONCLUSIONS: TIF with MUSE significantly improved symptoms at 1-year follow-up, allowing the consumption of PPIs to be stopped or halved in 90 % of patients.