Recent reports have established the feasibility of using balloon valvuloplasty to reduce left ventricular outflow tract obstruction due to a calcified aortic valve. The present study summarizes experiences with this technique in 9 patients (7 women, 2 men, mean age 78 years) in whom balloon valvuloplasty was used to treat calcific aortic stenosis. Peak aortic valve gradient (mm Hg) decreased from 68 +/- 8 (mean +/- standard error of the mean) before valvuloplasty to 35 +/- 5 after valvuloplasty (p = 0.003). Mean aortic valve gradient decreased from 57 +/- 7 before valvuloplasty to 30 +/- 5 after valvuloplasty (p = 0.006). Calculated aortic valve area increased from 0.42 +/- 0.04 to 0.81 +/- 0.06 cm2 (p = 0.005). Balloon valvuloplasty failed to diminish aortic valve obstruction in only 1 patient who, at subsequent surgery, had a congenitally bicuspid aortic valve. Significant aortic regurgitation was not observed in any of the 9 patients after valvuloplasty. One patient did have a highly focal, presumably embolic, brain stem infarct during the procedure. Femoral arterial blood loss, related to wire-guided exchange of balloon catheters too large for a 12Fr introducer sheath, was minimized by direct arterial exposure in 8 of the 9 patients. Thus, these findings confirm the efficacy of balloon valvuloplasty for the treatment of calcific aortic stenosis. The procedure, however, is not without hazard.