In the present investigation, a numerical study of the effect of the hot wall geometry on a laminar natural convection in an inclined square cavity, differentially heated, was undertaken. This problem is solved by using the partial differential equations which are the equation of mass, momentum and energy. The tests were performed for different inclination angles and Rayleigh numbers while the prandtl number was kept constant. Three geometrical configurations were considered. The results obtained show that the hot wall geometry affects the flow and the heat transfer rate in the cavity. The mean nusselt number decreases compared with the heat transfer in the square cavity.