Surface heterogeneity, geometric or energetic, can arise in various circumstances, e.g,, surface defects, porous adsorbents, surface of amorphous materials, etc. Much effort, both in theory and in simulations, has been devoted to study fluid absorption on perfect plane surfaces up to now, In contrast, many fundamental questions remain open concerning the effect of surface disorder on the structure and thermodynamic properties of adsorbates near heterogeneous surfaces. In this work, we propose a simple model for heterogeneous surfaces which allows us to address some of these questions by carrying out Monte Carlo simulations. An interesting feature of this model is that the counterpart with a structureless plane surface can be defined precisely for the model heterogeneous surface. Thus, meaningful comparison between the two cases can be made which have allowed us to clearly reveal the influence of surface heterogeneity on the fluid structure near rough surfaces. We also propose a simple approach which relates the fluid density profile near a heterogeneous surface to that near a plane surface through a distribution function characterizing the surface corrugation. Results in very good agreement with simulations have been obtained from this approach.