Isobaric vapor-liquid equilibria were obtained for l-butanol + chlorobenzene and for 2-butanol + chlorobenzene systems at 20 and 100 kPa using a dynamic still. The experimental error in temperature was +/-0.1 K, in pressure +/-0.01 kPa and +/-0.1 kPa for the experiments carried out at 20 and 100 kPa, respectively, and in liquid and vapor composition +/-0.001. The two systems satisfy the point-to-point thermodynamic consistency test. Both systems show a positive deviation from ideality. The data were correlated with the Wilson equation.