At the present moment worldwide waning fossil fuel resources as well as the tendency for developing new renewable biofuels have shifted the interest of the society towards finding novel alternative fuel sources. Biofuels have been put forward as one of a range of alternatives with lower emissions and a higher degree of fuel security and gives potential opportunities for rural and regional communities. Biodiesel has a great potential as an alternative diesel fuel. In this work, biodiesel was prepared from waste cooking oil it was converted into biodiesel through single step transesterification. Methanol with Potassium hydroxide as a catalyst was used for the transesterification process. The biodiesel was characterized by its fuel properties including acid value, cloud and pour points, water content, sediments, oxidation stability, carbon residue, flash point, kinematic viscosity, density according to IS: 15607-05 standards. The viscosity of the waste cooking oil biodiesel was found to be 4.05 mm2/sec at 400C. Flash point was found to be 1280C, water and sediment was 236mg/kg, 0 % respectively, carbon residue was 0.017%, total acid value was 0.2 mgKOH/g, cloud point was 40C and pour point was 120C. The results showed that one step transesterification was better and resulted in higher yield and better fuel properties. The research demonstrated that biodiesel obtained under optimum conditions from waste cooking oil was of good quality and could be used as a diesel fuel.