Increasing uncertainty about global energy production and supply, environmental concerns due to the use of fossil fuels, and the high price of petroleum products are the major reasons to search for alternatives to diesel. One of these alternative energy sources, biodiesel, can be produced from vegetable, animal, waste cooking and algal oils. Waste cooking oil (WCO) is one of the most economical choices to produce biodiesel. Since one of the major concerns in biodiesel production is the price of feedstock, utilization of WCO significantly enhances its economic viability. In this study, biodiesel was produced from WCO, using sodium hydroxide (NaOH) and methyl alcohol by transesterification method. Four different fuel blends (20, 40, 60 and 80% by volume, blending with diesel) were prepared. Specific gravity, density, kinematic viscosity, calorific value, flash point, copper strip corrosion and water content of biodiesel produced from WCO were determined under various blending ratios with ultimate euro diesel fuel, and also specific gravity and kinematic viscosity were investigated at different temperatures.