DEMs are essential for many geoscientific applications such as drainage and watershed, surface slope calculation, and ortho-image generation. Consequently, it is important to know the accuracy of the DEM as a function of the terrain topography and its derivative topographic surfaces. This paper shows results of DEM generated from different RADARSAT stereo pairs (fine, standard, extended) using an automated image matching over a rolling topography study site. The DEMs are then evaluated with a precise topographic derived DEM as a function of the terrain slopes and aspects. The DEM accuracy is correlated with the terrain slopes, but differently depending on the RADARSAT stereo geometry, and it is not correlated with the slope aspects.