Solid waste derived fuels are being increasingly considered for application in waste-to-energy processes. This thermal treatment methodology is becoming more popular since it deals with two major issues; the disposal of solid wastes and the production of a biomass-derived energy source. This paper is concerned with the analysis of a variety of waste derived fuels including mixed RDF, wood and paper, in comparison with coal. A specially designed chamber was developed to heat the fuels in an inert atmosphere whilst simultaneously measuring the internal temperatures of the pellets. The pellets were also tested for compressive strength, to determine how the devolatisation process affected the integrity of the pellets. Results showed that small RDF pellets devolatise very quickly in a high temperature environment, whereas larger paper pellets have far longer lifespans. Waste derived pellets lose structural integrity far quicker than coal-based fuels, which was identified as being linked to the composition of the materials and the mode by which they are held together. (C) 2007 Elsevier Ltd. All rights reserved.