Chemical interesterification of rubber seed oil has been investigated for four different designed orifice devices in a pilot scale hydrodynamic cavitation (HC) system. Upstream pressure within 1-3.5 bar induced cavities to intensify the process. An optimal orifice plate geometry was considered as plate with 1 mm dia hole having 21 holes at 3 bar inlet pressure. The optimisation results of interesterification were revealed by response surface methodology; methyl acetate to oil molar ratio of 14:1, catalyst amount of 0.75 wt.% and reaction time of 20 min at 50 degrees C. HC is compared to mechanical stirring (MS) at optimised values. The reaction rate constant and the frequency factor of HC were 3.4-fold shorter and 3.2-fold higher than MS. The interesterified product was characterised by following EN 14214 and ASTM D 6751 international standards. (C) 2017 Elsevier Ltd. All rights reserved.