The present study was intended to perform modelling as well as optimization studies for the extraction of essential oil from the leaves of lemongrass by hydro distillation. The models based on partitioning thermodynamics and kinetic desorption were studied to understand the extraction behaviour. The process was found to be influenced by the initial desorption step, described by the two-site kinetic desorption model. The optimum conditions, using the Taguchi method, were obtained as: 1:14 (w/w) solid to water ratio, 25 mm size of the plant material, extraction time of 1.5 h and 500W power. Solid to water ratio was found to be the most significant factor influencing the process. Moreover, qualitative analysis of essential oil was performed and the maximum amount of citral (83.24%) was obtained under optimized condition. The results obtained could provide a basis for higher scale study. (C) 2013 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.