An analytical expression is presented for the voltage response including the transient voltage for a simple (i. e., no concentration gradients) porous electrode model subject to a sinusoidal input current density. The transient voltage response as a function of the frequency, exchange current density, and double layer capacitance is studied independent of the periodic (steady state) voltage response. The change in the voltage response in the transient region is compared to that of the periodic voltage response with respect to the parameters. The physical properties of the porous electrode can be estimated using the voltage response in the transient region is presented. The methodology for doing this is described. (c) 2005 The Electrochemical Society.