Swallowing syncope is thought to be induced by an abnormal esophagovagal reflex arc that leads to transient bradyarrhythmia. Bradyarrhythmia in the response to swallowing produce decreased cardiac output and cerebral perfusion which result in loss of consciousness. Dysarrhythmia are common during any procedure which involves the manipulation of upper gastrointestinal tract, such as endoscopy of the esophagus or stomach. Swallowing syncope represents an extreme form of this phenomenon. We report a patient who had bradycardia and fainting episode during endoscopic examination. High degree atrioventricular block was detected in 24 hr Holter monitoring.