Background: gastroesophageal reflux disease (GERD) is a complex disease with multiple anatomic derangements. Laparoscopic sleeve gastrectomy (LSG) has many anatomic and physiologic effects such as lower esophageal sphincter pressure reduction, lack of gastric compliance, blunting of the angle of His and destruction of the phrenoesophageal ligament. Conflicting data exist for LSG and GERD. Assessment of the postulated high pressure in the gastric sleeve is very important in understanding GERD after LSG. Methods: A total of 40 morbidly obese patients were studied. The gastric pressure was measured using manometery preoperatively, at different steps intraoperatively and 24 hours postoperative. All patients are interviewed regarding their reflux symptoms using the GERD score questionnaire before and 6 months after LSG. Patients’ demographics and weight loss along with GERD were analyzed and correlated with pressure measurements. Results: 8 (20%) patients had preoperative GERD symptoms. 13 (32.5%) patients had post LSG GERD symptoms. The difference was not significant (P value= 0.1). 6 (15%) patients had a new onset GERD. 1 patient (2.5%) had relieved GERD symptoms post LSG. The mean relative pressure change (RPC) was 13.5 ± 6.0 cm H2O. The mean % EWL after 6 months of our patients was 45.4 ±15.8 %. There was a significant correlation between the patients’ age and RPC (P value=0.02). RPC was higher in the postoperative GERD patients but not significant (P = 0.1). Conclusion: The relationship between GERD and LSG is multifactorial. GERD did not resolve after LSG in most of our patients with pre existing GERD, and we had new onset GERD cases even with significant weight loss. The gastric pressure rise sharply after the sleeve creation, and then show a mild decline 24h. After recovery.