The impact of laparoscopic sleeve gastrectomy (LSG) on gastroesophageal reflux disease (GERD) has not been widely quantified, and the data in the literature remain controversial.Candidates for LSG underwent barium swallow, esophageal manometry, ambulatory 24-h esophageal pH monitoring (APM), and gastric emptying scintigraphy before and after surgery (1 and 18 months). Symptoms were evaluated using a gastroesophageal reflux disease questionnaire (GERDq). Esophagogastroduodenoscopy was performed preoperatively in all patients and at 18 months postoperatively in patients who had suffered from preoperative esophagitis.Fifty-two patients were included in the study (64.4% women and 34.6% men) with a median age of 46 years (25-63 years) and BMI of 45.0 ± 5.6 kg/mBased on the results of this study, LSG led to a considerable rate of postoperative "de novo" GERD. In addition, no improvement was found in patients with symptomatic GERD.