In the present work, the effect of ultrasound on the activity of lipase enzyme has been investigated using a probe-type sonicator capable of delivering variable power at a constant frequency of 20 kHz. It was observed that lipase enzyme gave a maximum activity at an ultrasound intensity of 12.22 W/cm(2) and an optimized sonication time of 9 min and any further increase in the intensity and time of sonication resulted in a decrease in activity. The maximum increase in the activity of the enzyme was 2-fold. All of the operating parameters were also optimized by the response surface methodology (RSM) approach. Immobilization of the enzyme was achieved after sonication at the optimized parameters to retain the activity of the enzyme, which gave 47.9% retention of the activity in the tributyrin hydrolysis reaction. Using the same reaction, the intensification phenomenon of the immobilized enzyme was also supported by thermodynamic studies, which showed considerable decreases in Delta G, Delta S, Delta H, and Delta E with sonicated enzyme as compared to the values obtained for reactions catalyzed with unsonicated immobilized enzyme.