In the current overview paper, various issues related to the combustion of agricultural residues are discussed. Attention has been given to the problems associated with the properties of the residues such as low bulk density, low ash melting points, high volatile matter contents and the presence of nitrogen, sulfur, chlorine and sometimes high moisture contents. Consequently the issues discussed include densification, the combustion mechanisms of agricultural residues, problems of low melting point of ash such as agglomeration and fouling, emissions and co-combustion. Further, design considerations of facilities for the combustion of agricultural residues are discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.