A 5-month-old girl with transposition of the great arteries, ventricular septal defect, and pulmonary stenosis underwent the implantation of a 6-mm M Atrial Flow Regulator (Occlutech) over an 8-French delivery sheath for significant cyanosis and progressive restriction of the atrial septal defect, without adverse event for 6 months. The Atrial Flow Regulator device could improve blood mixing as a bridge to surgery.