At the Experimental Pressurized Fluidized Bed Combustion Facility at Grimethorpe, South Yorkshire, UK, tests have been carried out over a wide range of operating conditions with the intent of developing a comprehensive set of PFBC performance data on combustion efficiency, sulphur retention, gaseous emissions, heat transfer, hot gas clean-up and component reliability, using a variety of coals. The materials monitoring and evaluation program is a part of the overall experimental program, and has the objectives of materials testing and evaluation, component monitoring and component failure analysis. This report describes the results of the materials program for the period of operation of the Facility from September 1980 to December 1981. Areas addressed in this report include the erosion and corrosion of a variety of uncooled metal alloy specimens, located at various positions within the bed: erosion, and a sulphation-oxidation type of corrosion are in evidence and the corrosion potential generally decreases with height above the distributor plate. The erosion of the in-bed tube bank was measured at the end of the operating period and wastage rates of approximately 0.1 to 0.3 mm/1000 h were observed. The performance and high temperature valves for the control of solids flow are described. Measures have been taken to improve the reliability of these components. 49 references, 37 figures, 12 tables.