Balloon dilatation of critical pulmonary valve stenosis in neonates with a weight of less than 2.5 kg is associated with specific problems, including temperature loss during the procedure, venous access, and problems related to the small size of the cardiac structures. We report our experience with balloon valvuloplasty in a premature newborn weighing 1.22 kg. Venous access was gained with a 4 French sheath, and balloon dilatation was performed with a 3.5 French 7-mm balloon catheter. Temperature loss of the baby was avoided by puncturing the femoral vein prior to the procedure on a neonatal open care system, wrapping the child in cotton, and covering the extremities with aluminium foil. The good result in our patient demonstrates that balloon valvuloplasty is a therapeutic option for treatment of critical pulmonary stenosis in premature infants.