The paper numerically analyses the necking of a cylindrical, elastic-plastic, strain-hardening bar in axisymmetric tension. Both geometric and material nonlinearities are taken into account. The Lagrangian formulation is used. The solution is obtained by a stepwise integration of the equilibrium equations, using the finite difference method. The results also include stress and strain distributions across the minimum bar section at various deformation stages up to 67% reduction of the bar's area. Comparisons with the results of previous investigators (Bridgman, Chen, Needleman, Norris) are also given. © 1979.