Abstract. Ventricular septal defect (VSD) is one of the most common congenital heart disease in children. When it is associated with high pulmonary hypertension (PH), the heart and lung experience increased pressure and workload, making early and accurate evaluation very important. Echocardiography is the main non-invasive method used to assess the defect. This study focuses on the echocardiographic features of VSD with PH in children and explains how these feelings help diagnosis, treatment planning and follow-up.