Background: Obese individuals have higher incidence of hiatal hernia (HH). There is controversy over the need for preoperative esophagogastroduodenoscopy (EGD) before bariatric procedures. The aim of this study is to determine the predictive value of preoperative endoscopy in diagnosing HH. Methods: Under IRB Approval A retrospective review of 402 cases who underwent sleeve gastrectomy (SG) in our academic center between January 2011 and December 2015 was performed. Patients who had preoperative EGD reports were enrolled in the study. Data were collected for the demographics, preoperative endoscopic and intraoperative findings. Each patient's EGD findings were compared with the intraoperative findings. Results: From total of 402 SG cases, 381 (81% female) had preoperative EGD. The mean age of the subjects was 45.8 years (± 10.6 years) with the mean BMI of 47.5 kg/m 2 (± 8.8 kg/m 2). There was no significant difference in age and BMI between males and females. 80 cases (20.5%) had a preoperative EGD that showed HH and 39 of those (48.7%) had intraoperative findings consistent with HH. 301 (79%) patients had no HH on preoperative EGD, out of which 286 (95%) patients were also negative for HH intraoperatively. Compared with intraoperative diagnosis, EGD had sensitivity of 67% and specificity of 85%. The negative predictive value of EGD was 96% for HH but the positive predictive value was 34%. Conclusions: EGD is a valuable informative tool in preoperative evaluation of bariatric patients. Our study demonstrated that EGD has high negative predictive value in ruling out HH but also with relatively low positive predictive value to prove its presence. Further studies are warranted to evaluate the discrepancies between the preoperative and intraoperative identification of HH, and standardization of definition for theses finding.