An oropharyngeal airway (OPA) is a medical device used to maintain an open airway in patients who are unconscious or unable to breathe adequately on their own. It is a curved plastic tube that is inserted into the mouth and extends into the throat, preventing the tongue from blocking the airway. OPAs are commonly used in emergency situations and during anesthesia. The OPA comes in various sizes to accommodate different ages and anatomies. Proper sizing is crucial for effective use; it should extend from the corner of the mouth to the angle of the jaw. It is important to note that OPAs should not be used in conscious patients, as they can trigger a gag reflex.