Pulmonary stenosis comprises variable pathologic features from the right ventricular outflow tract to the peripheral pulmonary arteries. Most frequently, the obstruction occurs at the level of the pulmonary valve; however, it occurs less frequently at the infindibular level. It can occur as part of more congenital cardiac malformations such as tetralogy of Fallot, complete transposition of great arteries, or atrial septal defect. Proximal pulmonary artery stenosis has also been reported as an acquired lesion in infants treated for congenital heart disease. Primary isolated supravalvular pulmonary stenosis is less common. We present a case of primary isolated pulmonary artery stenosis in an asymptomatic 25-day-old newborn infant.