Six neonates weighing ≤2,500 g with native coarctation of the aorta underwent balloon dilation. Of the 6 neonates, 4 were female and 2 were male, with a mean age of 14 days (range 9 to 20) and a mean weight of 1,900 g (range 790 to 2,500). The procedure was acutely successful in all 6 patients; the peak gradient decreased from 38 ± 19 mm Hg to 11 ± 3 mm Hg. The diameter increased from 1.5 ± 0.6 mm to 3.6 ± 0.7 mm. Of the 6 patients, 3 had required no additional intervention at a mean of 42 months after the initial dilation, and 3 had developed restenosis a mean of 2.4 months after the initial dilation and underwent successful redilation. Of the latter 3 patients, 2 developed restenosis and underwent surgical repair 37 and 68 days after the second dilation, and 1 of these patients developed recoarctation after surgery that was treated successfully with balloon dilation 54 days after the end-to-end repair. In conclusion, premature neonates weighing ≤2,500 g with coarctation of the aorta appear to respond acutely to balloon dilation. Some patients will have a successful long-term result after a single balloon dilation procedure. However, restenosis is common and tends to develop rapidly.