Congenital tracheal stenosis is a rare airway malformation. A high index of suspicion is fundamental. The authors report a case of congenital tracheal stenosis in a 13-month-old male infant, with a challenging diagnosis from the intensive care perspective. At birth, the patient presented an anorectal malformation with a recto-urethral fistula so a colostomy with mucous fistula was performed in the neonatal period. At the age of seven months, he was admitted due to a respiratory infection, treated with steroids and bronchodilators, and discharged after three days without any complications. He underwent complete repair of tetralogy of Fallot when he was 11 months old, which was performed without any reported perioperative complications. However, at the age of 13 months, due to another respiratory infection, he presented more severe symptoms and required admission to the pediatric intensive care unit (PICU) for invasive mechanical ventilation. He was intubated on the first attempt. While monitoring the difference between peak inspiratory and plateau pressures, we observed a sustained elevated difference between pressures suggestive of increased airway resistance, thus raising the possibility of an anatomical obstruction. Laryngotracheoscopy confirmed distal tracheal stenosis (grade II) with four complete tracheal rings. In our case, the absences of perioperative challenges or complications in previous respiratory infections were not suggestive of a tracheal malformation. Furthermore, no difficulties were encountered during intubation due to the distal location of the tracheal stenosis. A careful appreciation of respiratory mechanics on the ventilator at rest and during tracheal aspirations was essential to suspect an anatomical defect.