The purpose of the present work is to undertake a numerical study of natural convective heat transfer from a thin, two-sided, two-dimensional inclined plate having a uniform surface temperature. The surface shape is wavy, and attention has been given to both the case where the surface waves have a rectangular shape with constant height and to the case where the surface waves have a triangular shape with constant height. The temperature of the top and bottom plate surfaces, which are the same, is higher than the temperature of the surrounding fluid. Results for a wide range of dimensionless surface wave heights and for various inclination angles for both rectangular and triangular surface waves have been obtained and used to determine whether the presence of the waves can produce an enhancement in the heat transfer compared to that from a plane (non-wavy) inclined surface.