The molar heat capacity of Zn2GeO4, a material which exhibits negative thermal expansion below ambient temperatures, has been measured in the temperature range 0.5 less than or equal to (T/K) less than or equal to 400. At T = 298.15 K, the standard molar heat capacity is (131.86 +/-0.26) J (.) K-1 (.) mol(-1). Thermodynamic functions have been generated from smoothed fits of the experimental results. The standard molar entropy at T = 298.15 K is (145.12 +/- 0.29) J (.) K-1 (.) mol(-1). The existence of low-energy modes is supported by the excess heat capacity in Zn2GeO4 compared to the sums of the constituent binary oxides. (C) 2004 Elsevier Ltd. All rights reserved.