The effect of power ultrasound (20 kHz) on the dissolution rates of a spinning disk made from sparingly soluble benzoic acid was investigated. Ultrasound was found to intensify the dissolution rates especially at lower rotational speeds of the spinning disk. The ultrasonic intensification was found to decrease with increase in the rotational speed of the spinning disk. Empirical correlation was developed for the Sherwood number in the presence of ultrasound and mechanical rotation of the disk. From this, the intensification factor was derived in terms of ultrasonic power input and Reynolds number corresponding to the spinning disk. The intensification factor obtained in the current spinning disk configuration was compared with that obtained for the rotating cylinder configuration studied by Kannan and Pathan [Kannan, A.; Pathan, S. K. Enhancement of Solid Dissolution Process. Chem. Eng. J.2004, 102, 45.]. © 2011 American Chemical Society.