Vapor-liquid equilibrium (VLE) at 101.3 kPa have been determined for the ternary system ethanol + 2-butanone + 2,2,4-trimethylpentane (isooctane) and its constituent binary systems: ethanol + 2,2,4-trimethylpentane, ethanol + 2-butanone, and 2-butanone + 2,2,4-trimethylpentane. Minimum boiling azeotropes were observed for all these binary systems. No azeotropic behavior was found for the ternary system. Thermodynamic consistency tests were performed for all VLE data. The activity coefficients of the binary mixtures were satisfactorily correlated with the Wilson, NRTL, and UNIQUAC models. The models with their best-fitted binary parameters were used to predict the ternary vapor-liquid equilibrium. (c) 2007 Published by Elsevier B.V.