Ostial aortic stenosis is clearly the commonest form of valvular heart disease in adults at the present time, as it represents 26% of all forms of valvular heart disease and 2% of all forms of heart disease. It is a disease middle and old-age, which appears to becoming increasingly frequent due to ageing of the population. It affects men twice as often as women and sometimes has a misleading clinical presentation at the stage of heart failure due to disappearance of the usual systolic murmur. The patient may simply present with signs of refractory left ventricular failure or complete heart failure. The diagnosis and follow-up have been radically transformed by the development of Doppler ultrasonography which allows the positive diagnosis as well as a very precise assessment of the severity, avoiding the need for cardiac catheterization, but unfortunately coronary angiography still remains essential in view of the age of these patients. In terms of treatment, percutaneous valvuloplasty according to the method developed by Cribier has unfortunately not lived up to expectations and tight aortic stenosis remains a surgical disease whose results are among the most spectacular: the patient's dramatic functional and objective transformation following insertion of a valvular prosthesis (mechanical before the age of 75 years, bioprosthesis after this age), at the cost of a reasonable operative mortality of approximately 5 to 8% in the 71 to 80 year age-group, must be stressed.