For assessment of cerebrovascular diseases, it is beneficial to obtain information about the hemodynamics of the vessel system. Recently, we presented a method to quantify blood flow in a single blood vessel segment from rotational angiography. In this paper, we extend the method to bifurcations. A model- based method is proposed which estimates the mean flow, the waveform and the flow division at the bifurcation. The method is validated on experimental data using a phantom for a healthy and a stenosed carotid bifurcation. The average error for the estimate of the flow division was 8%.