A comparative study of temperature distribution in a roller compacted concrete dam during and after construction is carried out using two well known computers codes namely ANSYS and COSMOS. Two and threedimensional finite element models have been created and analyzed in order to understand and compare the results obtained based on the two computer codes. The influences of the thermal properties and the climatic condition, and the placement schedule of RCC layers were all considered in these analyses. The study demonstrated that the results of temperature computed using ANSYS numerical model analysis is relatively higher and more conservative than the COSMOS results. The available laboratory heat of hydration data and the incremental construction process of massconcrete structure can be modeled to produce results that can be used in practical applications, in case of Al-Wehdah RCC dam which was used in this study, the maximum temperature which was obtained by ANSYS is higher than the temperature that was obtained by COSMOS by one degree. Furthermore, the thermal results for both 2D and 3D analysis based on the two computer codes are very close to each other. Indicating, thus that there is no need to carry out the 3D finite element analysis to estimate the temperature distribution in the dam body.