A review of theory of the Self-Potential (SP) produced by groundwater flow is presented. On the basis of this theory a mathematical formulation and a method of SP numerical modelling is reviewed. The method is based on modelling of the groundwater flow and coupled electrical field. A modern field methodology that allows monitoring of SP within a studied site is discussed. Based on published data examples of SP application to pumping tests are reviewed. It is shown that in the course of well pumping a measurable electrical field can be produced and interpreted in terms of hydraulic parameters of aquifers. Refs 23. Figs 5. Table 1.