Densities and viscosities of binary mixtures of n-butyl acetate with acetophenone, cyclopentanone, cyclohexanone, and 3-pentanone were determined over the entire composition range at temperatures (298.15 to 313.15) K and at normal atmospheric pressure. From the experimental data, the excess molar volumes V-E and excess free energy of activation of viscous flow Delta G*(E) were calculated. These results were fitted to the Redlich-Kister polynomial equation. The excess molar volumes for all of the studied systems are negative over the whole composition range and at all of the studied temperatures. The experimental mixture viscosity data have been correlated using Grunberg-Nissan, Heric (two-parameter), and McAllister (four-body) models at different temperatures.