Background: Laparoscopic Nissen fundoplication (LNF) is the gold standard surgical intervention for gastroesophageal reflux disease (GERD). LNF can be followed by recurrent symptoms or complications affecting patient satisfaction. The aim of this study is to assess the value of the intraoperative endomanometric evaluation of esophagogastric competence and pressure combined with LNF in patients with large sliding hiatus hernia ( >5 cm) with severe GERD (DeMeester score > 100). Materials and methods: This is a retrospective, multicenter cohort study. Baseline characteristics, postoperative dysphagia and gas bloat syndrome, recurrent symptoms, and satisfaction were collected from a prospectively maintained database. Outcomes analyzed included recurrent reflux symptoms, postoperative side effects, and satisfaction with surgery. Results: Three hundred sixty patients were stratified into endomanometric LNF (180 patients, LNF + ) and LNF alone (180 patients, LNF). Recurrent heartburn (3.9 vs. 8.3%) and recurrent regurgitation (2.2 vs. 5%) showed a lower incidence in the LNF + group (P =0.012). Postoperative score III recurrent heartburn and score III regurgitations occurred in 0 vs. 3.3% and 0 vs. 2.8% cases in the LNF+ and LNF groups, respectively (P=0.005). Postoperative persistent dysphagia and gas bloat syndrome occurred in 1.75 vs. 5.6% and 0 vs. 3.9% of patients (P=0.001). Score III postoperative persistent dysphagia was 0 vs. 2.8% in the two groups (P =0.007). There was no redo surgery for dysphagia after LNF +. Patient satisfaction at the end of the study was 93.3 vs. 86.7% in both cohorts, respectively (P =0.05). Conclusions: Intraoperative high-resolution manometry and endoscopic were feasible in all patients, and the outcomes were favorable from an effectiveness and safety standpoint