We present a case of percutaneous closure of main pulmonary artery pseudoaneurysm using an atrial septal occluder device in a seven-month-old infant. The infant had tetralogy of Fallot repair followed by transcatheter left pulmonary artery stenting. The occlusion of the wide neck of the pseudoaneurysm was performed successfully using the atrial septal occluder with no detected complications in his six-month follow-up post-catheterisation.