The impact response of a three-dimensional human head model has been determined by simulating two cadaver tests. The objective of this study was to validate a finite-element human head model under different impact conditions by considering intracranial compressibility. The current University Louis Pasteur model was subjected initially to a direct head impact, of short (6 ms) duration, and the simulation results were compared with published experimental cadaver tests. The model response closely matched the experimental data. A long duration pulse was chosen for the second impact and this necessitated careful consideration of the head-neck joint in order to replicate the experimental kinematics. The skull was defined as a rigid body and was subjected to six velocities. Output from the model did not accurately match the experimental results and this clearly indicates that it is important to validate a finite-element head model under various impact conditions to define the range of validity. Lack of agreement for the second impact is attributed to the nonlinearity in the dynamic behavior of intracranial stress, a problem that is not reported in the literature.