Ultrasonication increases the chemical reaction speed of the transesterification of vegetable oils and animal fats into biodiesel. This allows to change the production from batch processing to continuous flow processing and it reduces investment and operational costs. Biodiesel is commonly produced in batch reactors using heat and mechanical mixing as energy input. Ultrasonic cavitational mixing is an effective alternative means to achieve a better mixing in commercial processing. Ultrasonic cavitation provides the necessary activation energy for the industrial transesterification process.