The mitral valve or bicupsid valve, formerly known as the mitral valve, is a valve located in the heart, connecting the left atrium to the left ventricle. It is also called the left atrioventricular valve.

The mitral valve consists of two parts: the valve apparatus and the sub-valvular apparatus. The valvular apparatus is the most complex and is composed of a fibrous ring surrounding the valve and of valvular leaflets originating from the fibrous ring and consisting of folds of the endocardium. The sub-valvular apparatus is composed of tendon cords and pillars.

Ventricular diastole is divided into 3 phases and constitutes relaxation, as opposed to systole which is contraction. During diastole, in the open position, the mitral valve has a funnel-like appearance.