||The present invention relates to an improved trileaflet mechanical heart valve 100 and an improved leaflet 110 for use with such valve. The valve 100 and leaflet 110 of the present invention provide improved flow characteristic, minimize blood clotting behind the leaflets, and provide more natural opening and clossing times. The valve includes a valve housing 105 which contains pivot/hinge mechanism (130,200, and 300) for allowing rotation of and retention of the leaflets 110. The valve housing 105 also includes windows or openings 125 which allows for complete washing of the pivot/hinge mechanism (13,200 and 300)as well as the leaflets 110. The novel leaflets 110 are airfoil-like having a complex S-shaped curvature on their outer surface. This novel geometry, when combined with the location of the leaflet's pivot axix,causes a tendency for the leaflet 110 to rotate towards the closed position. Thus, the leaflet 110 begins to close much earlier than a conventional leaflet and is substantially closed before the flow. reverses, similar to the function of a natural valve.