Advances in the study of erosive wear in corrosive conditions have lead to improved understanding of the performance of materials in such conditions. Through mapping the materials degradation as a function of the main process parameters, the most favourable operating conditions may be identified. The maps, albeit still in their infancy, provide the basis for addressing materials problems in erosion-corrosion environments in a non-empirical fashion. Where do we go from here? Much experimental work still needs to be carried out to understand the mechanisms of erosion-corrosion of the wide range of materials and coatings available for combating erosion-corrosion damage. Based on such work, mechanistic models of the damage processes need to be continually developed and refined in order that a sound basis can be generated for the construction of such maps from theoretical methods. This paper summarizes the recent work carried out on the development of materials performance maps both in wet and dry erosion-corrosion conditions. The future challenges for the research community of the work in this area are described. An outline route map through which these important developments may be carried out is also described. (C) 1999 Elsevier Science S.A. All rights reserved.