A dynamic rigid-plastic finite element method for simulating high-speed plastic deformation in the shot-peening processes is proposed on the basis of the finite deformation theory of plasticity. In the present method, the inertial force due to the decelerating shot is equilibrated with the force caused by plastic deformation of the workpiece at the interface in each deformation step. By the use of the stress distribution at the time of maximum inertial force calculated from the rigid-plastic analysis, the residual stress distribution in the shot-peened workpiece is obtained via the elastic finite element method. Three-dimensional plastic deformation and residual stress distributions in rectangular blocks peened with a single rigid shot are computed. The calculated shape and residual stress distribution of the shot-peened workpiece are in reasonable agreement with the experimental ones for mild steel, copper and aluminium blocks.