Isobaric vapour-liquid equilibrium (VLE) has been experimentally studied for the ternary mixture 2-butanol (1) + n-hexane (2) + 1-chlorobutane (3), at the pressure of 101.3kPa. The activity coefficients were found to be thermodynamically consistent and they were satisfactorily correlated with the Wilson, NRTL and UNIQUAC equations. They have been also compared with the results obtained from the application of the ASOG and the modified UNIFAC group contribution methods. The boiling points of the solutions were correlated with compositions by using the Wisniak-Tamir equations. The results obtained indicate that the ternary system deviates positively over the whole compositions range. Azeotropic behaviour was not found for the ternary mixture. (C) 2003 Elsevier B.V. All rights reserved.