Balloon atrial septostomy or Rashkind is a technique described almost half a century ago to dilate a preexisting atrial communication in order to enhance atrial mixing and to decompress the left atrium in congenital heart disease. With the contribution of fetal echocardiography this technique can be pre-planed, but, still many complications can arrive. It is done almost routinely in all case of transposition of the great arteries with restrictive interatrial communication. Many other techniques developed, but Rashkind intervention remains a reference in congenital heart interventions in newborn or small infant. It is a challenging procedure that needs trained interventional/congenital cardiologists and a well prepared catheterization laboratory, with the possibility for surgical or circulatory back-up. Nowadays, few complications can arrive, but are not to be neglected.