Experimental viscosities, η of pure benzene, 1,2-dichloroethane (DCE), 1,1,2,2-tetrachloroethane (TCE) and those of their binary mixtures, having benzene as a common component, have been measured over the whole composition range at 298.15, 303.15, 308.15, 313.15 and 318.15 K. The experimental η data were then fitted to standard polynomial against composition. Using η values, the deviations in viscosities, Δη, excess Gibbs free energies of activation of viscous flow, ΔG*E, entropies, ΔS* and enthalpies, ΔH* of activation of viscous flow have been calculated. The sign and magnitude of these parameters were found to be sensitive towards interactions prevailing in the studied systems. Further, the excess molar volumes, VE were calculated using data for both the binary mixtures. Moreover, Grunberg-Nissan and Isdale's group contribution methods have been used to calculate the viscosities of mixtures and the results were discussed in terms of average percentage deviations (APD) in experimentally and theoretically calculated viscosities.