This paper reviews literature on co-firing of coal with biomass fuels, Here, the term biomass includes organic matter produced as a result of photosynthesis as well as municipal, industrial and animal waste material. Brief summaries of the basic concepts involved in the combustion of coal and biomass fuels are presented, Different classes of co-firing methods are identified. Experimental results for a large variety of fuel blends and conditions are presented. Numerical studies are also discussed. Biomass and coal blend combustion is a promising combustion technology; however, significant development work is required before large-scale implementation can be realized. Issues related to successful implementation of coal biomass blend combustion are identified. (C) 2001 Published by Elsevier Science Ltd.