Capnography has become mandatory to monitor ventilation and enhance the safety of children during sedation procedures. Capnography alerts the clinicians of apnea and airway obstruction before the occurrence of hypoxia. Pediatric dentistry is no exception, and capnography can be used to monitor ventilation. Capnography also serves as an indirect monitor of cardiac output. An understanding principle of capnography is essential to precisely sample and monitor ventilation during sedation, particularly during oral procedures where dilution of expired gases by air, or concomitantly administered oxygen is a possibility. Many sampling devices are currently available and allow ventilation assessment during sedation.