A mathematical model was developed which accounts for the influence of nonuniform current distribution on the impedance response of a rotating disk electrode. Results obtained using this two‐dimensional model were compared against those using the one‐dimensional model for impedance developed by Tribollet and Newman. The one‐dimensional model was found to be adequate when kinetic limitations cause the current to be uniformly distributed. Significant differences between the one‐dimensional and two‐dimensional models were seen for fast reaction kinetics where the nonuniform ohmic potential distribution is balanced by a nonuniform concentration overpotential.