Obesity is associated with significant morbidity, with an estimated prevalence of 42.4% in the USA. Treatment of severe obesity often involves Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy. More recently, endoscopic sleeve gastroplasty has emerged as a minimally invasive option for patients with mild to moderate obesity. Endoluminal functional luminal impedance planimetry (EndoFLIP) uses impedance planimetry to assess tissue distensibility and geometric changes across an area but its role in bariatric surgery and bariatric endoscopy has not been fully elucidated. EndoFLIP has some utility in measuring gastric sleeve pouch size during sleeve surgery, assessing gastric sleeve stenosis, predicting the risk of post-sleeve GERD and response to endoscopic dilation, assisting in intraoperative gastric bands adjustment, and evaluating gastrojejunal anastomosis to predict weight regain after gastric bypass.