Prosthetic heart valves are commonly used as a treatment for aortic valve deficiencies. The performance of these prosthetic valves should be in accordance with the natural heart valve with respect to opening and closing, blood flow, and vortex formation. These performance parameters depend on the design of leaflets and overall geometrical parameters of the valve. To better understand the effects of leaflet design on the performance of the valve, we have carried out fully coupled fluid–structure interaction analyses of opening and closing of prosthetic heart valves with various leaflet designs. Maximum stress, valve opening, and flow stream pattern are obtained for different valve designs and used to assess the performance of the valves. The results show that the stress and the valve opening depend on the curvature and the inclination of the leaflets. A 3D model is designed based on the obtained results, and a full FSI analysis is performed to assess its performance. The results show that the presented design gives better values for valve opening area and leaflet stresses than that in the published data.