In a girl suffering from “Scimitar syndrome”, a rerouting of the scimitar vein was performed at the age of 6 years, but no embolisation of the aberrant systemic vessel was done. She presented with recurring respiratory problems 13 years later. An angiography revealed an invert flow from the aberrant systemic vessel via the right pulmonary artery into the left pulmonary artery. After pneumonectomy, she recovered well.