We consider a gas of N fermions at large (but fixed, independent of N) density. We show that the many-body time-evolution can be approximated by the nonlinear Hartree-Fock equation. We establish convergence at the level of reduced one-particle density matrices, proving global bounds in the Hilbert-Schmidt norm. For fermions with relativistic dispersion, we also obtain convergence for the expectation of local observables. This is a joint work with Luca Fresta and Marcello Porta.