The qualities of final biodiesel products were analyzed and the results showed that the physical properties of biodiesel produced with mechanical stirring and ultrasonication were within the ASTM standard ranges. Ultrasound power is an effective tool on in-situ transesterification during biodiesel production from soybeans. The future studies will include developing continuous in-situ transesterification systems that uses high intensity ultrasound for in-situ transesterification of soybean oil.