This work presents the isobaric vapor–liquid equilibrium (VLE) data for the binary mixture of butyl l-lactate + 1-butanol, which was measured at 1 and 5 kPa. The measurements were carried out in an equilibrium cell Fischer Labodest VLE 602D and binary mixtures were analyzed by gas chromatography. The experimental data reported were thermodynamically consistent according to the Van Ness and Fredenslund tests. The equilibrium was correlated with the nonrandom two-liquid (NRTL) and universal quasichemical (UNIQUAC) activity models with asymmetrical parameters. Both activity models present a very approximated correlation with experiments for being applied to the distillation process design, especially, at low-pressure conditions.