The bileaflet mitral valve is a highly complex organ in the body that regulates the blood that flows through the left atrium and into the left ventricle. It is designed to withstand decades of powerful forces within the pulsating chambers of the heart. The mitral valve’s bileaflet structure distinctly possesses two leaflets rather than three, unlike the other cardiac valves. When compared to the trileaflet valves, bileaflet mitral bioprosthetics face significant challenges due to structural complexity—nonplanarity in annulus shape, asymmetrical geometry, and heavily oriented collagen fibers. Understanding the mechanical properties that affect mitral valve biomechanics is crucial for developing bileaflet bioprosthetic designs. By use of finite element (FE) modeling and Abaqus computational packages, this project investigates the geometrical and structural properties of bileaflet mitral bioprosthetics that contribute to a reduction in stresses along the edges of the leaflet. The resulting data illuminates how the saddle-shape of the mitral annulus and fiber orientation affects stress distributions of the leaflet during simulated pressures. Incorporation of a fiber-aligned constitutive model contributes to significant variations in circumferential and radial stress/strains across the saddle-shaped bioprosthetic. Results indicate that circumferential stress is uniquely distributed away from the leaflet edges as an effect of the saddle-shape geometry. Future work using the knowledge gained from this project may use the correlation between the directionally-dependent tissue fibers and those stress/strain distributions to improve future mitral bileaflet bioprosthetic engineering designs.