Densities, viscosities, dielectric constants, and refractive indices have been determined for six binary mixtures of propyl acetate, butyl acetate, and ethyl butyrate in benzene and carbon tetrachloride at different mole fractions and temperatures. The excess volumesVE, apparent excess values of viscosity δη, excess Gibbs energy of activation of flow ΔG*E, excess molar polarizations, excess molar refraction, and excess dielectric constants ϵEhave been calculated from the experimental data. The results for these binary mixtures are compared with those of ethyl acetate with benzene, carbon tetrachloride, and cyclohexane and of propyl acetate, butyl acetate, and ethyl butyrate with cyclohexane. The results forVE, ΔG*E,, and ϵEindicate specific molecular interaction between unlike molecules in ester + benzene and ester + carbon tetrachloride. The specific molecular interaction for mixtures of esters with benzene may be due to n–π complex formation between the free electrons of carboxylic group and aromatic ring while with carbon tetrachloride it may be due to dipole – induced dipole interactions. The molar refractions for all six mixtures vary linearly with mole fraction of components. Comparison between experimental excess volumeVEand excess viscosity Δ ln η and that calculated from Flory theory for ethyl acetate + benzene and ethyl acetate + carbon tetrachloride has also been made.