A bite block for facilitating upper GI endoscopy procedures includes a body member that defines a first passageway, channel or lumen and a second passageway, channel or lumen. The first passageway is provided with a diaphragm for forming an airtight seal with an endoscope. The second passageway is connectable to a breathing apparatus for ventilating a patient. The body member includes a flange with a seal about a periphery thereof for engaging the face of a patient in an airtight fit about the mouth of the patient. Such a device facilitates the performance of upper endoscopic procedures by maintaining the integrity of the airway. The airway is spaced from the endoscope deployment pathway and can be maintained despite the movement of the endoscope.