Mitral valve stenosis (MS) can be congenital or acquired. Congenital MS is mainly the consequence of abnormalities of the subvalvular apparatus and occurs mainly in infants and children. [1] The congenital causes include parachute mitral valve deformity, congenital MS, supravalvular mitral ring and cor-triatriatum. The acquired causes of MS include rheumatic heart disease, left atrial (LA) myxoma, mitral annular calcification and thrombus formation. [1] Rheumatic MS is the most common form encountered in the developing world. The rheumatic disease process causes contracture, scarring, and diffuse thickening and fibrosis of the leaflet tissue, fusion and fibrosis of the commissures and the subvalvular apparatus, and calcium deposition within the leaflets. [2] These processes result in a decrease in the effective mitral valve orifice area (MVA) and manifestation of clinical features of MS. The main mechanism of rheumatic MS is commissural fusion. Other lesions such as chordal shortening and fusion, leaflet thickening and its calcification contribute to the restriction of leaflet motion. Degenerative MS is frequently observed in the elderly individuals, which differs markedly from rheumatic MS; the main lesion in it being annular calcification. Isolated calcification of the mitral annulus has few or no hemodynamic consequences, and it more often causes mitral regurgitation than MS. In degenerative MS, commissural fusion is rare, and the valve thickening or calcification predominates at the base of the leaflets whereas in rheumatic MS, the tips are predominantly affected. Protruding calcification, reduction of normal mitral annular dilatation during diastole [3,4] and impaired anterior mitral leaflet mobility, [5] are possible mechanisms responsible for the increased mitral gradient caused by mitral annular calcification. Other rarely encountered causes of MS include inflammatory diseases (e.g. systemic lupus erythematous), infiltrative diseases, carcinoid heart disease, and drug-induced valve diseases. In these situations, leaflet thickening and restriction is the cause of stenosis, and the fusion of commissures is rare.