Chili ingestion produces gastrointestinal symptoms in many subjects. Some of these symptoms, such as heartburn, might well arise from the esophagus, but the pathogenesis is unknown. We studied the effects of chili ingestion on esophageal motility in 16 healthy volunteers and correlated these with the production of chili-induced upper gastrointestinal symptoms. We also studied the effects of chili instillation into the esophagus in 15 of the subjects to determine whether typical symptoms were produced. There were no changes in esophageal manometric parameters in all 16 subjects after the ingestion of a chili suspension (5 g chili powder in 100 ml water), although half of them reported one or more symptoms. Direct instillation of the same chili suspension into the lower esophagus produced typical symptoms in all 15 volunteers tested. Chili-induced upper gastrointestinal symptoms were not accompanied by changes in esophageal motility. The esophageal mucosa itself was sensitive to chili, suggesting that at least some of the upper gastrointestinal symptoms produced by chili are mediated by direct stimulation of chili-sensitive afferent nerve endings in the esophageal mucosa.