The data on excess molar enthalpies, (Formula presented.), for binary mixtures (ethanol + water and acetic acid + ethyl acetate) and quaternary system (acetic acid + ethanol + ethyl acetate + water) at 313.15 K and standard pressure (101.303 kPa) were obtained using the Setaram C80 calorimeter. The results on excess enthalpies data were correlated by Redlich–Kister equations and NRTL model.