The effect of uncompensated resistance, R(u), on the cyclic voltammetric response of an electrochemically reversible surface-attached redox couple is quantified using simulation. When current density and interfacial potential are uniform across the electrode surface, the shift in the peak potential, E(peak) - E(0)', the peak current, i(peak), and uncompensated resistance, R(u), can be correlated by a simple, general, empirical expression: [GRAPHICS] When the value of (nF/RT)|E(peak) - E(0') | double right arrow 0. (E(peak) - E(0)')/i(peak)R(u) double right arrow 2; when the value of (nF/RT)|E(peak)-E(0)'| double right arrow infinity the value of (E(peak) - E(0)')/i(peak)R(u) double right arrow 1.0; these limiting values are independent of the double layer capacitance, C(dl). For intermediate values this expression is adequately accurate as long as RTC(dl)/n(2)F(2)Gamma (total) <= 0.1. (C) 2008 Elsevier B.V. All rights reserved.