Dynamic viscosities at T = 298.15 K and atmospheric pressure have been measured over the whole composition range for (methyl acetate + methanol + 2-propanol, or 2-butanol, or 2-methyl-2-butanol) and (methyl acetate or methanol + 2-methyl-2-butanol). Viscosity deviations for binary and ternary systems were calculated and fitted to Redlich-Kister and Cibulka equations, respectively, in order to estimate the parameters and the standard deviations between the calculated and the experimental data. To predict the viscosity of ternary mixtures several methods have been proposed, some of them are based on contribution groups and the others use the binary correlation parameters. Some methods of excess properties, which determine ternary values by means of binary contributions, have been applied.