Calcific aortic stenosis is the most common valvular heart disease in the Western world. Although definitive treatment is valve replacement, many patients are not replacement candidates due to high surgical risk from older age and comorbid illness or lack of desire for a surgical or replacement procedure. Percutaneous balloon aortic valvuloplasty (BAV) is an option for palliative treatment in nonsurgical patients, although this procedure is complicated during the immediate postprocedure period by bleeding requiring transfusion for about 1 in 5 patients and subsequent restenosis. This report describes BAV using a smaller profile balloon designed to withstand higher pressures, rapidly inflated with a power injector. Twenty consecutive high-risk patients with severe aortic stenosis were treated. In all cases, New York Heart Association (NYHA) class improved from IV before BAV to I or II at 30 days follow-up. Six-month posttreatment follow-up data were available for 19 of 20 patients: 15 patients were either NYHA class I or II, 1 patient was class III, and 3 deaths occurred unrelated to aortic stenosis. One patient was lost to follow-up. Average systolic gradient peak-to-peak pressure decreased by 40.0% (range 18.0-70.0%) and mean gradient decreased by 30.0% (range 13.7-70.8%). Aortic valve area increased from 0.59 ± 0.16 cm(2) to 0.92 ± 0.23 cm(2), representing a mean increase of 30.0% (range 7.8%-58.2%). There were no significant bleeding complications. The only procedural complication was a single case of pericardial tamponade. There were no other complications during the first 24 hours post-BAV. These data support that the reported BAV technique may offer an effective alternative for patients with severe aortic stenosis who are not surgical candidates or prefer to avoid aortic valve replacement.