The molar heat capacity of ammonium hexafluorogermanate (NH4)(2)GeF6 was measured from T approximate to 5 K to T = 326 K by adiabatic calorimetry. Our results show that neither a transition nor the metastability that sometimes occurs in R2MX6 compounds was present. From our results, the standard molar entropy Delta(0)(T)S(m)(0){(NH4)(2)GeF6, cr}/R = (36.30 +/- 0.04), where T = 298.15 K and R = 8.31451 J.K-1 mol(-1); on the basis of this result, the function Phi(m)(0){(NH4)(2)GeF6, cr}/R = (17.87 +/- 0.03) at T = 298.15 K. Smoothed values of the standard thermodynamic functions are tabulated to T = 320 K.