Vascular access-related complications are an important consideration in patients undergoing cardiac catheterisation. Patients with CHD are increasingly undergoing percutaneous treatment for suitable procedures as an alternative, less invasive option to surgical intervention. As such, recognition and treatment of these complications are becoming increasingly important. We present a case of a patient with repaired Tetralogy of Fallot who developed a femoral arteriovenous fistula and femoral artery pseudoaneurysm arising from an accessory arterial branch following percutaneous Harmony valve implantation, both of which were treated endovascularly with placement of a stent.