The densities, viscosities, refractive indexes, and surface tensions of ternary mixtures of 2,2,4-trimethylpentane (isooctane) + cyclohexane + decane at 298.15 K and atmospheric pressure were measured. The experimental values of viscosity were correlated with the mole fractions of the components using the McAllister and Grumberg-Nissan equations. These experimental data have been used to calculate deviations. The results were fitted to the Redlich-Kister equation.