Rigorous and approximate analytical expressions are deduced for Differential Pulse Voltammetry at spherical electrodes of any size, including microelectrodes, when the electrogenerated species is soluble in the electrolytic solution. From these, we examine the utility of DPV for the determination of diffusion coefficients and formal potentials, establishing the optimum conditions for this purpose. The experimental validation of the theoretical results is reported for mercury microelectrodes of ca. 50 and 10 mu m diameters both in aqueous and ionic liquid media. (C) 2009 Elsevier B.V. All rights reserved.