<p>One of the prevalent theories used to describe electrokinetic phenomena that occur in saturated porous media, due to the existence of electric double layers (EDLs) at solid–fluid interfaces—namely, Pride’s theory-, is revisited in this paper. Among the central assumptions of this theory, it is considered that the diffuse layers of the EDLs remain unperturbed by the action of an external source, which is justified if there exists a high electric permittivity contrast between the constituents of the media. However, this contrast may not be high enough in typical scenarios of interest, and, in addition, the perturbation of the diffuse layers plays an important physical role in electrokinetic phenomena. In this work it is shown that, maintaining the rest of its assumptions, the theory’s range of validity can be extended to scenarios of arbitrary permittivity contrast. The main remaining assumptions that allow this result to be obtained are (i) the thin EDL hypothesis, (ii) ideal electrolyte behavior, (iii) bulk electroneutrality, (iv) moderate <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(\zeta \)</EquationSource> <EquationSource Format="MATHML"><math> <mi>ζ</mi> </math></EquationSource> </InlineEquation>-potentials (less than 100 mV for the thickest possible EDLs in a thin EDL regime), and (v) a steady-state regime of charge continuity at the pore-scale. Assumption (v) in particular implies that the complete dielectric dispersion caused by the perturbation of the diffuse layers lies outside the scope of Pride’s theory; a criterion is given in order to determine porous media and frequencies where this assumption holds. A comparison with an established electrokinetic model is made, showing good results; and a final discussion is given regarding the scope of the theory.</p>