Due to the intrinsic features of laser annealing treatments in semiconductors, i.e., localized irradiation with a space- and time-dependent thermal field that leads to far-from-equilibrium conditions, experimental analysis can reveal only specimen postirradiation characteristics. In order to understand how the laser-irradiated system evolves and reaches its final state, a theoretical work based on full process simulation is required. Traditional models for laser processing simulation were based on continuum techniques. However, they prove to be insufficient at the nanoscale. Atomistic simulation techniques, in turn, are handy for studying detailed interactions, at both electronic and atomic levels, including out-of-equilibrium situations as those present in laser processing. In this chapter, we review the main techniques for atomistic simulation to be applied for laser modeling. We also present some recent results on atomistic …