Viscosities of the ternary mixture (cyclohexane + tetrahydrofuran + chlorocyclohexane) and the binary mixtures (cyclohexane + tetrahydrofurane and cyclohexane + chlorocyclohexane) have been measured at normal pressure at the temperatures of 298.15 and 313.15 K. The viscosity data for the binary and ternary mixtures were fitted to a McAllister-type equation [R.A. McAllister, AIChE J. 6 (1960) 427-431]. Viscosity deviations for the binary and ternary mixtures were fitted to Redlich-Kister's and Cibulka's equations [I. Cibulka, Cell. Czech. Chem. Commun. 47 (1982) 1414-1419]. The group contribution method proposed by Wu [D.T. Wu, Fluid Phase Equilib. 30 (1986) 149-156] has been used to predict the viscosity of the binary and ternary systems.