In Pulmonary Atresia with Intact septum (PA-IVS) pulmonary valve is atretic, right ventricle (RV) size is variable depending on tricuspid valve (TV) status. When TV is hypoplastic, RV is also hypoplastic known as ‘hypoplastic right heart syndrome’. Intramyocardial sinusoids in the small and thick RV are present. When TV is relatively competent, blood comes to RV, goes through the myocardial sinusoids to coronary arteries and returns back to RA through coronary sinus, known as circular shunt. Right atrium (RA) is dilated with obligatory right to left shunt across ASD/PFO. It is a duct dependent lesion. Pulmonary flow depends on persistence of ductus arteriosus. Neonates become critically ill with onset of closure of duct. Neonatal cyanosis, LV apex, no significant murmur and in ECG showing normal axis, RA enlargement and LV dominance give strong suspicion of PA-IVS. In X-ray, cardiomegaly with pulmonary olegimia is present. Aortic arch is always left sided. Echocardiography confirms the diagnosis showing imperforate thickened and immobile pulmonary valve with a well formed pulmonary artery, presence of ductus, well-developed LV and a thick walled small RV. Catheterization and angiography is mandatory before surgery. Recent advancement in interventional and newer surgical procedures have made the outlook better.