The Cardioseal/Starflex septal occluder is usually deployed through a long transvenous sheath for closure of atrial septal defects, persistent foramen ovale, and, less commonly, ventricular septal defects. We describe two patients with residual left-to-right shunting after surgical palliation of congenital heart defects and illustrate the successful use of the double-umbrella device in these situations using a retrograde transarterial approach. This is exemplified by two previously not described interventions: retrograde closure of a large muscular ventricular septal defect in a patient after a palliative Mustard operation and a transcatheter closure of a Waterston-Cooley anastomosis. Effective and safe closure of left-to-right shunting can be achieved by retrograde use of the Cardioseal/Starflex device in selected adolescents and grown-ups with congenital heart disease.