The transfer of Cs+ and TMA+ (tetramethylammonium) cations across the water-nitrobenzene interface was studied by the cyclic voltammetry method in the temperature range 5–65°C. With the use of simple thermodynamic cycles, the changes of the enthalpy and entropy of individual transfer of several univalent cations (Li+, Na+, H+, K+, Rb+, Cs+ and TMA+) and dipicrylaminate anion (DPA−) from the aqueous phase into the nitrobenzene phase were determined from the temperature dependences of polarographic half-wave potentials corresponding to transfer of Cs+ and TMA+ ions across the interface studied and from some previously published thermodynamic data. The transfers were found to be endothermic with the Li+, Na+ and H+ ions and exothermic with the K+, Rb+, Cs+, TMA+, and DPA− ions. Furthermore, the transfer of each of the above-mentioned ions from the aqueous phase into the nitrobenzene phase was proved to be accompanied by entropy drop.