Nonceliac gluten sensitivity (NCGS) is the clinical term used to describe gastrointestinal (GI) and/or extraintestinal symptoms associated with gluten ingestion. The prevalence of NCGS is unknown. The condition has clinical features that overlap with those of celiac disease (CD) and wheat allergy (WA). The pathophysiologic process in NCGS is thought to be through an innate immune mechanism, whereas CD and WA are autoimmune- and allergen-mediated, respectively. However, dietary triggers other than gluten, such as the fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, have been implicated. Currently, no clinical biomarker is available to diagnose NCGS. Exclusion of CD and WA is necessary in the evaluation of a patient suspected to have NCGS. The onset of symptoms in patients with NCGS can occur within hours or days of gluten ingestion. Patients with NCGS have GI and extraintestinal symptoms that typically disappear when gluten-containing grains are eliminated from their diets. However, most patients suspected to have NCGS have already initiated a gluten-free diet at the time of an evaluation. A gluten elimination diet followed by a monitored open challenge of gluten intake to document recurrence of GI and/or extraintestinal symptoms can sometimes be helpful. If NCGS is strongly suggested, then a skilled dietitian with experience in counseling on gluten-free diets can provide proper patient education. Additional research studies are warranted to further our understanding of NCGS, including its pathogenesis and epidemiology, and to identify a biomarker to facilitate diagnosis and patient selection for proper management.