BACKGROUND Cornelia de Lange syndrome (CdLS) is a congenital multisystemic genetic disorder. The expected lifespan of children with this disorder has been prolonged in parallel with the advances in medicine in recent years. However, they still more frequently undergo cardiac surgery. There are some challenges for clinicians when faced with CdLS patients. We present the perioperative management of a child with CdLS undergoing open-heart surgery. CASE SUMMARY Severe pulmonic and subpulmonic valvular stenosis, enlargement of the right side of the heart, mild tricuspid regurgitation, atrial septal defect, and patent ductus arteriosus were diagnosed in a 14-month-old boy with manifested cyanosis, developmental delay, and malnutrition. Attempted balloon valvuloplasty was unsuccessful due to a severe stenotic pulmonary valve, therefore it was decided to perform an open surgical repair. Following a successful and uncomplicated intraoperative course, the patient was extubated on postoperative day 5, and adrenalin and dopamine infusions were gradually decreased and stopped on postoperative days 6 and 10, respectively. Moderate laryngomalacia and suboptimal vocal cord movements were diagnosed, and tracheotomy and percutaneous endoscopic gastrostomy were performed under general anesthesia in the same session at postoperative day 32. The patient was discharged on postoperative day 85 after a challenging postoperative period with additional airway and nutritional problems. CONCLUSION This is the first report of the perioperative anesthetic and clinical management of a CdLS patient undergoing open-heart surgery.