The use of alcohol as fuel for internal combustion engines is developed from a historical perspective to present-day technology. Methods of producing the common fuel alcohols, methanol and ethanol, are discussed together with economic considerations.The properties of alcohol fuels are detailed in comparison with those of petroleum fuels. The characteristics which affect health and safety are pointed out.The use of alcohol and alcohol blends in gasoline and diesel engines is examined. Experimental diesel engine modifications to incorporate alcohol combustion with that of diesel fuel are analyzed for various available technologies. These include mechanical emulsification with diesel fuel, fumigation and in-cylinder injection of alcohol. Performance, energy consumption and emissions results are examined as well as safety and engine durability concerns.The development status of ignition-assisted diesels and spark-ignited stratified-charge engines is reported. An extensive bibliography is included.