Densities, viscosities, and refractive indices are investigated for binar, mixtures of 1,2,3,4-tetrahydronaphthalene with several n-alkanes, namely, octane, nonane, and decane, at different temperatures (293.15 K, 298.15 K, 303.15 K, and 313.15 K) and atmospheric pressure. The values of density (rho) of the compounds were used to compute excess molar volume (V-m(E)) of the solution. The refractive indices of these binary systems were also determined over the whole concentration range at 293.15 K and 303.15 K.