Double-skin facade provides many opportunities for energy conservation in buildings. This work summarizes the results of a computational fluid dynamic (CFD) analysis, which was carried out to investigate the effect of blind and thermal mass concrete on the thermal performance of a double-skin facade. Navier-Stokes equations, turbulent k-epsilon model, and discrete ordinates radiation model have been used to simulate the airflow and to study the airflow pattern. It was shown that the airflow patterns for natural ventilation with a blind and thermal mass concrete were very complex with multiple vortex structures. On the other hand, the heat flux and the airflow velocity at the inlet have a significant impact on the natural ventilation airflow rate. The Rayleigh number for turbulent flow was in the range of 10(7) <= Ra <= 10(8) using a blind. However, the Rayleigh number was less than 10(7) using thermal mass concrete. On the other hand, thermal mass increases the energy performance of natural ventilation. A good agreement was performed by comparing the experimental data and the simulation results.