Biodiesel is a renewable bio-fuel derived from natural fats or vegetable oils, and it is an attractive alternative to replace diesel fuels. Currently, the main disadvantage could be the high costs of some types of raw materials. The main purpose of this research is, therefore, to develop the optimum condition biodiesel production method from a low cost of raw material Aregmone Ocheroleuca seed oil and methanol alcohol by transesterification reactions. In the present investigation the effect of acid pretreatment of oil, the effect of catalyst amount, temperature, and alcohol to oil molar ratio. Special attention was paid to the optimization of base-catalyzed on the conversion of fatty acid methyl ester (FAME). The Aregmone Ocheroleuca oil used in the esterification contained 12.5 mg KOH/g of acid and after acid pretreatment; it was possible to bring down the acid value to 1.59 mg KOH/g. After the pretreatment process, to determine the optimum condition for transesterification of Aregmone Ocheroleuca oil using methanol and potassium hydroxide as input, 18 experiments varying methanol-to-oil molar ratio (3:1,4:1 and 6:1), reaction temperature (45,55, and 65OC), and amount of catalyst (0.5 and 1%). Reaction time and mixing intensity were fixed to 2 hrs, and 350 rpm respectively. The optimum conditions found for transesterification were a methanol-to-oil molar ratio of 6:1, a reaction temperature of 55OC and an amount of catalyst of 1%. At the optimum condition obtained a FAME conversion of 93.4% v/v was achieved and a produced biodiesel property has a viscosity of 3.95mm2/s, Acid value of 0.34, HHV of 41.20 MJ/kg, iodine value of 40.7 gI2/100ml density of 871.8 Kg/m3, Flashpoint 166.7OC and Cetane number of 54.63.