The enthalpy of formation at 298.15 K and low temperature heat capacity of Cs3Na(MoO4)(2) have been measured for the first time in this work using solution calorimetry and thermal-relaxation calorimetry in the temperature range T = (1.9-299.6) K, respectively. The solution calorimetry measurements, performed in 2 M HNO3 solution, have yielded an enthalpy equal to Delta H-r(m)(298.15 K) = (6.79 +/- 1.72) kJ.mol(-1) for the reaction: 3/2Cs(2)MoO(4)(cr) + 1/2Na(2)MoO(4)(cr) = Cs3Na(MoO4)(2)(cr) Combining with the enthalpies of formation of Cs2MoO4(cr) and Na2MoO4(cr), also determined in this work in 0.1 M CsOH and 0.1 M NaOH solutions, respectively, the standard enthalpy of formation of Cs3Na(MoO4)(2) at 298.15 K has been determined as Delta H-f(m)o(Cs3Na(MoO4)(2), cr, 298.15 K) = -(2998.5 +/- 3.0) kJ.mol(-1). The heat capacity and entropy values of Cs3Na(MoO4)(2) at 298.15 K have been derived as C-p,m(o)(Cs3Na(MoO4)(2), cr; 298.15 K) = (296.3 +/- 3.3) J.K-1.mol(-1) and S-m(o)(Cs3Na(MoO4)(2), cr, 298.15 K) = (467.2 +/- 6.8) J.K-1.mol(-1). Combining the newly determined thermodynamic functions, the Gibbs energy of formation of Cs3Na(MoO4)(2) at 298.15 K has been derived as Delta(f)G(m)(o)(Cs3Na(MoO4)(2), cr, 298.15 K) = -(2784.6 +/- 3.4) kJ.mol(-1). Finally, the enthalpies, entropies and Gibbs energies of formation of Cs3Na (MoO4)(2) from its constituting binary and ternary oxides have been calculated. (C) 2018 The Author(s). Published by Elsevier Ltd.