Percutaneous balloon pericardiotomy (PBP) has been used in patients with recurrent pericardial effusions in which the chest and pericardium had not been previously entered and therefore concerns about adhesions were minimal. Few reports have depicted PBP for patients with recurrent pericardial effusions following open-heart surgery, in which adhesions may play a greater role. We report a successful creation of a pericardial window using PBP in a child with recurrent pericardial effusions after a Fontan revision. This technique offers a simpler approach to the treatment of recurrent pericardial effusions after open-heart surgery in patients with 8 congenital heart disease.