Heat capacities of the alpha- and the beta-phase of trielaidin were measured from 10 to 360 K. The enthalpy of fusion of the stable beta-phase was found to be 177.4 J.g(-1), the triple point temperature was 314.83 K, and the calculated purity, assuming eutectic behavior of the main component and the impurity, was 96.66 mol %. The enthalpy of fusion of the metastable alpha-phase was calculated to be 95.1 J.g(-1); the melting temperature was estimated to be 288 K from differential scanning calorimetry experiments. The heat capacity of the liquid phase can be given by a simple linear fit between 320 K and 360 K: (cp)(l) = (1.327 + 0.002529T/K) J.K-1.g(-1). To obtain a thermodynamically consistent set of entropy and enthalpy data for both forms, a zero entropy of 0.037 J.K-1.g(-1) and a zero enthalpy of 41.48 J.g(-1) had to be used for the alpha-phase. The origin of these values is discussed.