Laryngeal cysts are rare in adults; therefore, the majority of previous reports deal primarily with laryngeal cysts in infants and children. Ductal cysts of the larynx arise from the submucous glands when the ducts of these glands are occluded. They are most commonly located in the vallecula. In this report, we present a rare cause of life-threatening stridor in adults, a large ductal cyst of the larynx that was removed via endoscopic CO2 laser resection. On the basis of clinical observations during the postoperative period, we conclude that endoscopic CO2 laser resection is a reliable and safe method for removing cysts of the larynx. It is also a cost-effective procedure that minimizes hospitalization time and the need for tracheotomy.