This paper briefly reviews the use of hazelnut oil as an alternative fuel in pre-chamber diesel engines, and compares it with diesel fuel. In order to investigate the effects of the use of hazelnut oil as a diesel engine fuel, an experimental setup was constructed. The results showed that the hazelnut oil may be. employed as a possible candidate for most diesel fuel operating conditions in terms of the performance and emission parameters without any modification and preheating of the fuels. (C) 2006 Elsevier Ltd. All rights reserved.