Vlasov simulations of stimulated Raman scattering (SRS) are presented, both for low laser irradiance when the plasma waves remain linear and for high laser irradiance when particle trapping occurs. At low irradiance the energy in scattered radiation and in plasma kinetic energy approach values given by the Manley–Rowe relations. At high irradiance the effective damping rate of the plasma waves is greatly increased over the Landau damping rate while electron trapping is occurring. A relativistic model for electron trapping has been developed. It yields expressions for the number and maximum energy of the trapped electrons and the threshold for their production. Forward SRS dominates at high plasma temperatures and produces faster trapped electrons compared to backward SRS.