In this paper, measurements of the heat capacities and thermal diffusivities of commercial CMSX-4 nickel-based superalloy are described, and the results are presented. Since the as-received commercial alloy sample is not at the thermodynamic equilibrium state, the phases present in the alloy undergo transformations toward equilibrium state as the measurements are made at temperatures above which the rate of transformation can be significant. The microstructures of the as-received sample as well as heat treated samples were observed, and the relation with the properties was discussed. The results are discussed considering the phase changes Occurring with the thermodynamic equilibrium state as the reference. The results are of great relevance in the performance of these alloys in industrial applications.