Natural evolution presumably optimizes biological systems, however, the optimality criteria are not explicit and thus unknown to the human observer. Specifically, the vascular system may obey design principles such as volume minimization or power loss minimization, but these assumptions must be verified by examining the technical optima and comparing them to real biological systems. In this thesis we are concerned with the computational aspects of simulation and optimization of vascular bifurcations, which are the basic design elements of the vascular system. We simulate three-dimensional flow in vascular bifurcations by numerically solving stationary Navier-Stokes equations using the method of finite elements. In continuation of previous work we plan to adapt the Navier-Stokes equations with terms more accurately describing the biological phenomena associated with blood flow. Also, we would like to utilize evolutionary computation methods to artificially evolve optimal bifurcation geometries.