Many types of vegetable oils and their methyl esters were tested in diesel engines as an alternative fuel. Melon has a high potential of production. Wasted Melon kernel, generally has a high oil ratio and similar properties with other biodiesel sources and can be used for biodiesel production. In this study, the oil was produced from melon kernel and then converted to the biodiesel. The effects of pure melon kernel oil methyl ester (MKOME) and its 2% and 20% blends with Diesel fuel no.2. on performance and emissions was investigated in a single cylinder, direct injection diesel engine at full load and various engine speeds. Melon kernel oil methyl ester blended with diesel by 2% produced slightly higher torque, power and nitrogen oxides emission along with lower carbon monoxide, hydrocarbon and smoke density. Torque, power, carbon monoxide and hydrocarbon emissions were decreased as the ratio of melon kernel oil methyl ester is increased. The lowest Hydrocarbon emission was measured for 20% melon kernel oil methyl ester-diesel fuel blend.