Nonerosive reflux disease (NERD) is the most common phenotype of gastroesophageal reflux disease. By definition, patients with NERD have typical reflux symptoms caused by the intraesophageal reflux of gastric contents but have no visible esophageal mucosal injury. This is in contrast to patients with erosive reflux disease (ERD) or Barrett's esophagus (BE) who have obvious esophageal mucosal injury on endosco-py. Only 50% of patients with NERD have pathologic esophageal acid exposure as detected on 24-h pH monitoring. NERD patients with physiologic esophageal acid exposure and good temporal correlation of symptoms with reflux events are considered to have esophageal hypersensitivity, while patients with no symptom-reflux correlation are considered to have functional heartburn. It is possible yet uncommon for NERD to progress to severe ERD (i.e. LA Grade C or D) or BE. Patients with NERD and pathologic esophageal acid exposure have motor dysfunction and acid reflux abnormalities that are similar to patients with ERD and BE, whereas NERD patients with physiologic esophageal acid exposure have minimal abnormalities and are not much different than healthy controls. The pathological feature most indicative of NERD is the presence of dilated intercellular spaces within squamous epithelium, an ultrastructural abnormality readily identified on transmission electron microscopy but also on light microscopy. A symptomatic response to an empiric trial of high-dose proton pump inhibitor (PPI) therapy is a simple and useful strategy to establish the diagnosis of NERD, although histology and pH monitoring may be useful in confirming the diagnosis. Patients with NERD suffer similar decrements in quality of life as do patients with erosive esophagitis. Therapy is aimed at eliminating or reducing symptoms and improving quality of life. PPIs are the most effective agents for the treatment of NERD although they are less effective in providing symptom relief than in patients with erosive esophagitis. Laparoscopic antireflux surgery is an effective therapy for selected patients with NERD and outcomes are better when performed in high volume centers.