Vallecular cyst is a rare but dangerous cause of stridor in neonates and young infants. Without recognition and proper therapy, the resulting airway obstruction can lead to serious morbidity and mortality. We herein report a young infant with a vallecular cyst synchronous with laryngomalacia and gastroesophageal reflux. The infant initially presented with signs and symptoms mimicking more benign laryngomalacia. Diagnosis was delayed with accompanying failure to thrive. The cyst was revealed by a barium esophagogram and confirmed by flexible bronchoscopy. Laryngomicrosurgery with CO(2) laser not only removed the cyst, but resolved the co-existing laryngomalacia and gastroesophageal reflux as well. After surgery, the infant was symptom free and exhibited a steady weight gain. There was no recurrence during 1 year of follow-up. We have reviewed the literature for this rare and potentially devastating lesion.