The classical ultrasonically induced reaction of the decomposition of aqueous KI Solution has been studied on a 501 hydrodynamic cavitation set-up. This reaction, which has been previously studied using acoustic cavitation, has been shown to be influenced by hydrodynamic cavitation as well. Methodology has been suggested to enhance the reaction rates, when using hydrodynamic cavitation set-up. Manipulation of the throttling device (orifice plates) and the operating conditions have increased the iodine liberation rates, three times more than acoustic cavitation at equivalent power dissipation rates. The scale-up possibilities of hydrodynamic cavitation as a means of an alternative to acoustic cavitation have been discussed.