The application of concentrated solar energy on the surface alloying of molybdenum-based powder on 304L stainless steel is attempted in this work. The treated surfaces are thoroughly examined by means of optical and scanning electron microscopy (SEM) and characterized by electron dispersive spectroscopy (EDS). The characteristics of the obtained surface alloys (depth, microstructure, chemical composition, hardness) are related to the type of the heating process applied and to the main experimental parameters: heating rate, maximum temperature (T-maX), duration of maintenance (t(maint)) at T-max and total time of exposure (t(total)). (C) 2005 Elsevier B.V. All rights reserved.