: Gastroesophageal reflux disease (GERD) seems to be a common complaint which persists or develops after metabolic bariatric surgery (MBS). Endoscopic evaluation is vital in both the preoperative and postoperative phases to ensure optimal patient outcomes. The aim of this study was to evaluate the prevalence of GERD after MBS in a 10-year follow-up and analyze the endoscopic outcomes. : This retrospective, multicenter study included 368 patients who underwent single bariatric procedure. The data came from five bariatric centers in Poland, part of the BARI-10-POL project. Data on symptoms of GERD, endoscopic findings, demographics, and surgical outcomes were collected for a 10-year follow-up period. Surgical procedures included SG, Roux-en-Y gastric bypass (RYGB), and one anastomosis gastric bypass (OAGB). : Of the 305 patients without symptoms of GERD, 12.3% developed de novo GERD postoperatively. There was no statistical significance regarding the new-onset symptoms and the type of MBS ( = 0.074) and the presence of symptoms of GERD and the type of MBS ( = 0.208). However, SG was associated with a significantly lower likelihood of GERD remission after MBS ( = 0.005). Endoscopic evaluation showed abnormal findings in asymptomatic patients in both preoperative (35.8%) and postoperative (14.1%) examinations ( < 0.001). : GERD may be a common issue after MBS. One-quarter of patients after MBS may experience symptoms of GERD, regardless of the type of MBS. SG appears to be associated with a higher risk of persistent symptoms of GERD and a lower likelihood of GERD remission after MBS. Asymptomatic patients both before and after MBS may have abnormal findings in gastroscopy.