Densities and viscosities of ternary mixtures of benzylchloride+nitrobenzene+isobutanol and three corresponding binary mixtures (benzyl chloride+isobutanol, benzyl chloride+nitrobenzene, and nitrobenzene+isobutanol) have been determined over the whole concentration at a temperature range of 288.15 to 313.15K under atmospheric pressure. Experimental data of resulting mixtures were used to calculate viscosity deviations, ln, and excess energies of activation of viscous flow, G*E, of the ternary system. The calculated data for binary mixtures have been fitted by the Redlich-Kister equation to determine the appropriate coefficients. In order to determine the coefficients of ternary data, Cibulka, Singh, and Nakata equations were used. The results have also provided a test for the Grunberg and Nissan equation for correlating the dynamic viscosities of binary and ternary mixtures with mole fractions.