AbstractTreatment for peripheral pulmonary artery stenosis is challenging, and conventional balloon angioplasty has not proved to be universally effective. Evaluated was the efficacy of bladed balloon (BB) dilation to address vessels resistant to conventional high‐pressure (10–15 atm) balloon angioplasty (BA). Thirty‐one procedures were performed on 14 children with age range 1 month to 15 years. The diameter of the BB ranged from 3 to 8 mm. After BB dilation, all children had subsequent conventional BA (balloon size range, 3–10 mm). The minimal lumen diameter (MLD) before and after the procedure, whether there was a waist at initial BA, and BB diameter‐to‐MLD ratio before the procedure were measured. A > 50% increase in MLD was considered successful. Four children had Williams syndrome, two children Alagille syndrome, five children Fallot's tetralogy, and three miscellaneous lesions. The resistant stenosis was located in the right central pulmonary artery in 6, right branch pulmonary artery in 7, left central pulmonary artery in 6, and left branch pulmonary artery in 12 lesions. Median BB diameter was 253% (117–440%) of the MLD and increased from 2.0 ± 0.7 to 3.2 ± 0.8 mm (P < 0.0001), with a mean increase of 73% ± 62%. There was an inverse relationship between the MLD before and increase after the procedure (r = 0.75; P < 0.001). The BB diameter‐to‐MLD ratio before procedure was significantly associated with the increase in MLD (r = 0.70; P < 0.001). After the procedure, 18 of the 31 procedures were considered successful. In all successful procedures, the BB diameter was greater than twice the MLD before the procedure. Comparing children with Williams and Alagille syndrome with the remaining eight children, there were no significant differences in the increase in MLD. A small aneurysm and thrombus were noticed in two and three children, respectively, but no fatal complications were reported. BB angioplasty is effective for resistant peripheral pulmonary artery stenosis when conventional BA fails. The diameter of the BB should be larger than twice the minimal luminal diameter of the stenotic lesion. Catheter Cardiovasc Interv 2004;62:71–77. © 2004 Wiley‐Liss, Inc.