Densities, viscosities, refractive indices of binary liquid mixtures composed of methyl formate and o-, m- and p-xylenes were determined at 303.15K and atmospheric pressure for the whole range of composition. From the experimental results the deviation in viscosity (Delta eta), excess Gibbs free energy of activation of flow (Delta G*(E)), and the deviation in molar refraction (Delta R) were deduced. The deviation in viscosities were correlated with Redlich-Kister polynomial equation. The Delta eta values are negative while the values of Delta G*(E) are positive and the Delta R values are both positive and negative over the entire range of composition for all the studied systems. The ability of different one parameter and two parameter and two parameter empirical models to predict mixing viscosities was also studied.