A skull-brain finite element model of the human head has been developed using digital CT and MRI data. This reference model was validated on the basis of modal characteristics and the transient response. The calculated eigenfrequencies were in the same range as found in literature. The calculated intracranial pressures were comparable to those measured by Nahum et al. . The objective of a parametric study has been to assess the importance of both the geometrical detail to which the components are modeled and the conditions at their interfaces. We conclude a proper characterization of the constitutive properties under impact conditions is of the utmost importance. Further the relative motion at the skull-brain interface has a much larger influence on the intracranial pressures and stresses than the detailed modeling of the structures of the intracranial contents.