The aim of this study is to investigate the deposition remains of fuel droplets that impinge on a hot surface of Aluminum Alloy. The fuel droplets tested are diesel fuel (DF) and palm oil based ester that refers as a bio-diesel fuel (BDF). Temperatures of Aluminum Alloy surface and impingement interval of droplets are two parameters that were considered for various conditions of experiments. The maximum evaporation point (MEP) obtained from evaporation characteristics for each fuel was used as a reference point to decide the surface temperature of the Aluminum Alloy, where deposits of fuel were observed. The impingement interval was set at 3, 5 and 8 s with various surface temperatures of 320 degrees C and 370 degrees C. To understand the effect of heat transfer on deposition development, surface temperature of deposits was measured by using infrared thermometer. The deposition development depended on a few factors such as droplet impingement interval, hot surface temperature, type of fuel, and heat transfer of fuel deposits. BDF produced rapid development of fuel deposits comparing to DF. (C) 2007 Elsevier Ltd. All rights reserved.