A prospective, randomized, multicenter trial has demonstrated that cutting-balloon therapy increases lumen diameter to a greater extent than high-pressure balloon angioplasty (85% versus 52%, P = 0.004) in pediatric patients with congenital pulmonary stenosis. Although the study was not powered to show a difference in safety, the two forms of treatment were found to have similar safety profiles; no serious adverse events occurred in either group. Cutting-balloon therapy could become the treatment of choice for the ∼30% of cases in which the lesion is unresponsive to high-pressure balloon angioplasty.