The viscosity and density of ternary mixtures of toluene (1) + cyclohexane (2) + pentane (3) have been measured at 298.15 K and atmospheric pressure over the entire range of compositions. Excess molar volumes (V (E)) and viscosity deviations (Delta eta) were obtained from the experimental results for the binary and ternary systems and fitted to Redlich-Kister's and Cibulka's equations in terms of mole fractions. The V-123(E), data was positive, and inversion of the sign was observed over some concentrations at x approximate to 0.2 for Mixtures at three fixed compositions (f(m) = x(1)/x(2)). The Delta eta(123) data were negative values at three fixed compositions. The results obtained for excess molar volume and viscosity of liquid mixtures were used to test the semiempirical relations of Tsao-Smith, Jacob-Fitzner, Kohler, Rastogi et al., Radojkovic et al., Colinet, Toop, and Scatchard et al. The experimental and the constituted ternaries are analyzed to discuss the nature and strength of intermolecular interactions in these mixtures.