In this work, a methodology for analysis and characterization of different ash fractions (bottom ash, 2-3rd pass ash, super-heater ash, economizer ash and filter ash) generated from the incineration of MSW in a grate firing plant is presented. The methodology is shown to provide detailed information regarding the chemical composition and the main characteristics of the generated fly and bottom ash that could provide valuable information concerning the handling of ash-related problems (slagging, fouling, corrosion), and also ash disposal problems. Comparison of the results obtained with results from corrosion studies with MSW ash showed that the sampling point and the sampling procedure significantly affect the results obtained. (c) 2005 Elsevier Ltd. All rights reserved.