Trisomy 18 is a genetic disease resulting from an extra chromosome 18, characterized by a broad clinical spectrum, poor prognosis and low rates of survival. This is the case of a 12 year-old girl diagnosed with full trisomy 18, and multiple malformations, including Dandy-Walker Syndrome and congenital heart defects on long term survival. At nine months, a new echocardiogram showed a double outlet right ventricle, significant pulmonary stenosis, patent ductus arteriosus and ventricular septal defect. Cardiac surgery was performed at one year and seven months. Early surgical intervention and multidisciplinary follow-up may change the clinical outcome of the disease. Further studies are required to evaluate the benefit of invasive procedures such as cardiac surgery on survival of patients with trisomy 18.