Balloon valvuloplasty has already gained its place as an alternative option in the treatment of valvar stenoses. In congenital valvar stenosis its application will be limited because of the complexity of the underlying valve deformities. Nevertheless, isolated pulmonary and aortic valve stenosis are amenable to this form of treatment. The major limitations are undeveloped arterial valve rings and valve dysplasia. In acquired valvar stenosis the main limitation of balloon valvuloplasty seems to be massive calcification of the affected valves. Basically, in both the arterial and atrioventricular position, balloon valvuloplasty splits fused commissures and fractures calcific deposits. Excessive radial pressures may cause tears of the leaflets. The potential of thromboembolic complications, therefore, warrants caution. The nature of the damage inflicted on pathologic valves almost by necessity dictates that restenosis will occur and - most likely - with a high incidence.