The aim of this study is to reveal incidence of gastroesophageal reflux disease (GERD) after laparoscopic sleeve gastrectomy (LSG) and to determine the effect of LSG with hiatal hernia repair on GERD. A total of 440 patients, 395 of them underwent primary LSG (group A) and 45 of them underwent LSG with concomitant hiatal hernia repair (group B) between March 2018 and September 2020 were included in the study. Presence of hiatal hernia was evaluated with endoscopy and confirmed intraoperatively. Patients were evaluated for GERD symptoms in the pre and postoperative period. Two groups' data were compared. Mean age of the 440 patients was 38.4±11 years (56% female) and mean body mass index was 44.2±7 kg/m 2 . Symptomatic GERD was detected in 103 (23.4%) and hiatal hernia was detected in 45 (10.2%) patients. İn the preoperative assessment there was no difference with regard to demographics and symptomatic GERD between the 2 groups. Mean duration of follow-up was 17±5.7 (12 to 28) months in the overall study population. Mean body mass index decreased to 28.3±4.9 kg/m 2 at 12 months after LSG. Excess weight loss ratio was found to be 81±20.4%. The rate of symptomatic GERD after LSG in group A was found to be 20% (n=79/395). Of these patients, 46 (11.6%) had de novo GERD and 33 (38%) had persistent GERD. GERD resolved completely in 54 (62%) patients. In the group B, the rate of symptomatic GERD was detected as 33% (n=15/45) ( P =0.04). The rate of de novo GERD (20%) was also higher in group B ( P =0.03). The rate of persistent GERD (37%) and GERD resolution (62%) were similar in both groups. İn our study, symptomatic and de novo GERD rates were detected to be higher in the LSG+HH group than LSG alone.