The paper begins by examining the reasons for using alcohol fuels as a replacement for petroleum-derived fuels. The wide range of sources of alcohols enable most nations to undertake production of indigenous supplies. In general alcohols are excellent fuels for the spark-ignition engine of traditional design. Alcohol is quite unsuited in combustion properties for the more efficient unthrottled compression-ignition (diesel) engine. The reasons for this are explained and various means of overcoming the problems are outlined—additives for cetane improvement, alcohol-diesel emulsions, dual injection, fumigation, surface ignition and spark ignition. In each case the practical drawbacks as well as the benefits are discussed. Finally some conclusions are drawn about the potential for alcohol-fuelled diesel engines based on the authors' studies and experimental work.