A critical analysis of current methods for dealing with the problem of electrostatic field calculations for systems of charged particles in dielectric media is presented. The applicability of the approximation which assumes the identity of the field created by the charges in vacuum and the induction vector—broadly used in electrostatic calculations in solution theory—is analysed. There are then discussed three cavity models which describe the medium as: (i) local uniform dielectric (ε= const), (ii) local nonuniform dielectric (ε=ε(r)), (iii) dielectric with spatial dispersion (ε(r, r′)).