A lattice gas model formalism under mean field approximation is developed for the analysis of differential capacitance pertaining to liquid/liquid interfaces. The interfacial profiles for the two solvent mole fractions are chosen and ionic charge densities are estimated by minimizing the Helmholtz free energy. The dependence of the differential capacitance on various interaction energies, electrolyte concentrations and dielectric constants is indicated. The influence of the solvent density profile is analyzed and deviations from the predictions of Gouy-Chapman theory are pointed out. (c) 2005 Published by Elsevier Inc.