Solubility, critical states and liquid-liquid equilibrium (LLE) data for the quaternary system acetic acid-ethanol-ethyl acetate-water and for the ternary subsystems acetic acid-ethyl acetate-water and ethanol-ethyl acetate-water were studied at 303.15 K and 313.15 K and atmospheric pressure. Binodal surfaces, binodal curves, tie-lines and compositions of critical points were determined. In order to construct the binodal surfaces and critical curves of the quaternary system, five quaternary sectional planes with several different ratios of concentration of acetic acid to ethanol were studied. Experimental LLE data were compared with the values calculated by UNIFAC and NRTL models, and it was found that the experimental and calculated data are in good agreement. (C) 2014 Elsevier B.V. All rights reserved.