Background: RefluxStop™ is an implantable, non-active, single use device used in the laparoscopic treatment of GERD. RefluxStop™ aims to block the movement of the LES up into the thorax and keep the angle of His in its original, anatomically correct position. This new device restores normal anatomy, leaving the food passageway unaffected. Methods: In a prospective, single arm, multicentric clinical investigation analyzing safety and effectiveness of the RefluxStop™ device to treat GERD, 50 subjects with chronic GERD were operated using a standardized surgical technique between December 2016 and September 2017. They were followed up for 1 year (CE-mark investigation 6months). Primary safety outcome was prevalence of serious adverse events related to the device, and primary effectiveness outcome reduction of GERD symptoms based on GERD-HRQL score. Secondary outcomes were prevalence of adverse events other than serious adverse events, reduction of total acid exposure time in 24-h pH monitoring, and reduction in average daily PPI usage and subject satisfaction. Results: There were no serious adverse events related to the device. Average GERD-HRQL total score at 1 year improved 86% from baseline (p < 0.001). 24-h pH monitoring compared to baseline showed a mean reduction percentage of overall time with pH < 4 from 16.35 to 0.80% at the 6-month visit (p < 0.001), with 98% of subjects showing normal 24-h pH. At 1 year: No new cases of dysphagia were recorded, present in 2 subjects, which existed already at baseline. Regular daily PPI usage occurred in all 50 subjects at baseline. At 1-year follow-up, only 1 subject took regular daily PPIs due to a too low placement of the device thereby prohibiting its function. None or minimal occasional episodes of regurgitation occurred in 97.8% of evaluable subjects. Gas bloating disappeared in 30 subjects and improved in 7 subjects.