On the premise that the increased average life expectancy and a reduced incidence of rheumatic diseases have changed the epidemiological profile of valvulopathies, the paper analyses the causes, pathological anatomy, physiopathology and therapy of aortic valvular stenosis. First of all, the differences of acquired calcific stenosis, in which the orifice may be "forced" by the ventricular pump leading to a late onset of symptoms, are underlined. Clinical symptomatology must include angina, syncope or decompensation, rather than merely and elevated gradient, before surgical therapy is proposed. In addition to traditional therapeutic methods (valvular replacement) there is now the possibility of using balloon valvuloplasty which has provided good results in terms of increased valvular area and recovery of ventricular function; however, this is only a palliative step in cases where major surgery is contra-indicated.