The activity of zinc in liquid-tellurium-saturated CdTe-ZnTe solid solutions in the temperature range 743-848 K was measured by an electrochemical technique using LiCl-KCl + 5 wt% ZnCl2 as the molten salt electrolyte. The activity of cadmium was estimated from hypothetical e.m.f. values and also by Gibbs-Duhem integration. The activity values of Zn and Cd calculated at different temperatures were used to obtain various partial and excess molar thermodynamic quantities, namely Delta ($) over bar G(Zn)(M), Delta ($) over bar G(Zn)(XS), Delta ($) over bar H-Zn(M), Delta ($) over bar S-Zn(M), Delta ($) over bar S-Zn(XS), Delta ($) over bar G(Cd)(M), Delta ($) over bar G(Cd)(XS), Delta ($) over bar H-Cd(M), Delta ($) over bar S-Cd(M) and Delta ($) over bar S-Cd(XS). The thermodynamic data obtained in the present investigation are consistent with the view that the CdTe-ZnTe system consists of a single phase throughout the entire range of composition.