Abstract: An endoscopic breathing mask configured to fit over the mouth and nose of a patient has an air tube positioned so that oxygen can be continuously and controllably introduced into the mask. A bite-block is provided for gripping by a patient's teeth. The bite-block is hollow to accommodate introduction of an endoscope thereinto. A Luer-lock port is provided for connection to a capnograph for monitoring respiration for apneic conditions that may lead to potentially fatal hypoxia. An adjustable strap is provided for securing the mask to the patient. A beaded edge surrounds the mask to provide rigidity as well as provide greater comfort to the patient. A plurality of openings is provided for the passive diffusion of a patients expiratory gases.