A new set of parameters for NRTL activity coefficient model was correlated, for the quaternary mixture acetic acid/isoamyl alcohol/isoamyl acetate/water based on the experimental vapor-liquid and liquid-liquid equilibrium data. A complete and consistent thermodynamic topological characterization of the non-reactive and reactive mixtures was proposed, checking if the consistency equations of the residue curve maps are satisfied. The structure of the residue curve maps for the non-reactive quaternary mixture presents three binary azeotropes and one ternary azeotrope. No reactive azeotropes were found for the reactive mixture. The new set of NRTL activity model parameters presented better predictive capabilities for liquid-liquid and vapor-liquid phase equilibria than current available models. A successful liquid-liquid equilibrium phase stability test was also performed using the adjusted model. The results can be used to achieve conceptual design and simulation of conventional and intensified chemical processes for the isoamyl acetate production. (C) 2013 Elsevier B.V. All rights reserved.