A model for metal-oxide surge arresters, derived from that one recommended from the IEEE W.G. 3.4.11, is presented. The main innovation introduced by the paper lies in the simplicity of the criteria proposed for the model's parameter identification. Such criteria allow calculation of the model parameters directly from the standard data reported in the arrester data-sheets with a simple and straightforward procedure. The effectiveness of the model was tested for several arresters of different manufacturer both for medium voltage and for high voltage application. The discharge test results obtained by the manufacturers were compared with the results of simulations performed with the Alternative Transient Program (ATP). Effectiveness and simplicity of use make the proposed model a useful tool for insulation coordination studies involving steep front transients.