In our department, percutaneous balloon valvuloplasty has become the routine treatment of aortic valve stenosis in adults. We report here the results obtained in 245 consecutive patients. The patients' age varied between 30 and 98 years (mean 74 +/- 11 years), 77 of them (31 p. 100) being 80 years' old or older. The initial peak to peak ventriculo-aortic gradient was 72 +/- 25 mmHg and the aortic valve area was 0.53 +/- 0.17 cm2. After dilatation the gradient was reduced to 29 +/- 14 mmHg (p less than 0.001) and the aortic valve area was increased to 0.95 +/- 0.33 cm2 (p less than 0.0001). The aortic valve area was increased by 100 p. 100 or more in 83 patients (34 p. 100) and by less than 25 p. 100 in only 17 patients (7 p. 100). The ventricular ejection fraction rose slightly but significantly from 48 +/- 18 p. 100 to 51 +/- 17 p. 100 (p less than 0.01). One patient developed massive regurgitation and had to undergo semi-emergency surgery. The experience acquired and the use of better catheters enabled us to improve these results by almost doubling the number of patients whose aortic valve area became 1 cm2 or more and by reducing by half those whose aortic valve area remained 0.7 cm2 or less. Three patients aged 82, 91 and 98 respectively died, and there was one cerebral vascular accident in the catheterization room. Nine patients (4 p. 100) died in hospital during the following days.(ABSTRACT TRUNCATED AT 250 WORDS)