The aim of study is to synthesize a biodiesel from soybean oil using ultrasonic process. At present, biodiesel is produced in batch reactors in which the required energy is provided by heating by mechanical mixing. Alternatively, ultrasonic processing is an effective way to attain required mixing providing the necessary activation energy. Ultrasonic is a very desirable tool for producing biodiesel from vegetable oil and animal fats, because it lowers the cost of processing, speeds up transesterification, does not require elevated temperatures, and produces a higher grade of biodiesel. The aspect considered in the research work is to develop and design a methodology for ultrasonic process. Hence, our main aim is to study the effect of ultrasonic irradiation on the production of biodiesel from soyabean oil with homogeneous catalysts (KOH). Different operational parameters affecting the biodiesel yield, including methanol/oil molar ratio, catalyst type and concentration, reaction time, and ultrasound pulsation rate were evaluated.