Viscosities of binary liquid mixtures of butan-2-one with benzene were measured at a number of mole fractions at T = (303.15, 313.15, and 323.15) K and atmospheric pressure. The viscometric behavior is discussed on the basis of structural and geometrical effects between the components. In addition, kinematic viscosities were calculated using the UNIFAC−VISCO model. The predicted kinematic viscosities are in good agreement with the experimental ones.