Abstract Background: Laparoscopic Sleeve Gastrectomy (LSG) is one of the safest and most effective bariatric surgeries but carries the risk of gastro-esophageal reflux disease (GERD) and the hiatus hernia (HH) development. The effect of HH identification and repair during LSG on GERD is controversial. Aim of Study: In this study we evaluate the outcome of hiatal dissection and posterior crural repair if HH was found during LSG on GERD symptoms and post-operative weight loss. Patients and Methods: This was a prospective study involving 100 patients who underwent LSG in Ain Shams University Hospitals, Patients were sequentially divided into 2 groups: Group A was the hiatal dissection group (no 50) in whom hiatal dissection was performed and posterior crural repair was done if HH was found while group B (no 50) was the non-hiatal dissection group in whom dissection stopped when the left crus of the diaphragm was reached, and sleeve gastrectomy (SG) was done alone. Both groups were followed for one year and compared regarding intra and post-operative complications, self-reported reflux symptoms and percentage of excess weight loss (%EWL). Results: Females represented 66% of patients, the mean age was 30.32 and 30.20 years, the mean pre-operative BMI was 41.12 and 43.2kg/m2 while the mean pre-operative health related quality of life index (HRQLI) score was 5.72 and 7.08 for group A and B respectively. Intra-operative blood loss for both groups was comparable, the mean operative time was significantly longer in group A which was 84.64mins in comparison to 49.92mins for group B, there were no intra-operative complications in both groups. Hiatal dissection in group A revealed 8 cases (16%) of HH. Six cases of bleeding in both groups four in group A and two in group B, no leakage and one case of right lower limb DVT in group A two weeks after surgery. The mean GERD HRQLI scores were better for group A (with statistically significant difference at 9 months and highly significant difference at 12 months follow-up), while the %EWL was highly significant better after the 6th and 9th months for group A. Conclusion: Active search for HH and its repair, if found, during SG has favorable outcome on post-operative reflux symptoms and weight loss with acceptable increase in the operative time.