The viscosities of fourteen binary mixtures of methyl methacrylate (MMA), ethyl methacrylate (EMA) or butyl methacrylate (BMA) with n-hexane, n-heptane, carbon tetrachloride, chlorobenzene or o-dichlorobenzene were measured at 303.15 K. The mixture viscosities were found to correlate reasonably well with the Grunberg-Nissan, Heric, McAllister and Auslaender equations. The dependence of the derived viscosity deviations both on the size of the alkyl chain in the ester molecules and on the nature of the second component revealed the complex nature of the interactions in these mixtures. The equimolar mixture viscosities of MMA-containing mixtures were analysed by the Bloomfield-Dewan approach on the basis of Flory free-volume theory and the thermodynamic contributions, viz. enthalpy, entropy and free volume terms, were evaluated. The results of the analysis show that dispersing interactions are predominant in the aliphatic hydrocarbon- and carbon tetrachloride-containing mixtures, while both specific and dispersing interactions were found to contribute equally in binary mixtures of MMA and chlorobenzenes.