The standard molar Gibbs energy of formation of La2Zr2O7 from La2O3 and ZrO2 has been determined in the temperature range 1073 K to 1273 K by the e.m.f. measurements. The solid-state galvanic cell involving lanthanum beta-alumina electrolyte was applied. The average values of the standard enthalpy and the standard entropy in the temperature range covered by the e.m.f. measurements have also been estimated, The results have been compared with those obtained by other authors.