Application of ultrasound-assisted biodiesel production process from Jatropha oil catalyzed by activated carbon-supported tungstophosphoric acid catalyst was studied. Influences of ultrasonic energy on different process variables were elucidated. Reaction variables i.e. reaction time (10–50 min), reactants' molar ratio (5:1–25:1), ultrasonic amplitude (30–90% of the maximum sonifier power) and catalyst amount (2.5–4.5 w/w oil) were studied. A mathematical representation for biodiesel yield was successfully generated. A yield of 91% was achieved in just 40 min at a moderate ultrasonic amplitude (∼60%), high molar ratio (25:1) and low reaction temperature (65 °C). Interactions between the variables were also validated statistically. Leaching study revealed that the reaction was predominately heterogeneous in nature.