Background: Sedation for gastrointestinal endoscopy improves patient comfort but is associated with respiratory depression and hypoxemia, particularly with agents such as propofol and opioids. Airway obstruction is more pronounced in high-risk patients, necessitating simple and effective airway safety strategies during spontaneous ventilation. Case Presentation: We describe a case series in which a nasopharyngeal airway (NPA) connected to a circle system was used to maintain airway patency and spontaneous ventilation during gastrointestinal endoscopy. This technique provided effective oxygenation, minimized airway obstruction, and ensured procedural safety without the need for advanced airway devices. The approach was comparable to Transnasal Humidified Rapid-Insufflation Ventilatory Exchange in supporting airway patency. Conclusion: The use of an NPA with a circle system is a safe, simple, and effective method for airway management during endoscopy, enhancing airway safety while preserving spontaneous ventilation.