Densities and viscosities of binary nonelectrolyte systems including nitrobenzene + 2-propanol, 2-butanol and 2-pentanol at temperatures 293.15 to 323.15 K and normal atmospheric pressure were measured using an Anton-Paar SVM3000 Stabinger viscometer. Excess molar volumes Vm E and viscosity deviations Δηwere calculated and correlated by the Redlich–Kister equation to estimate the standard uncertainty. These values are negative over the full range of composition for all studied mixtures. Free volume theory coupled with the Peng–Robinson equation of state was used to correlate liquid viscosities of pure compounds and binary mixtures. The agreement between measured viscosity data and values calculated from this model is within experimental uncertainties.