Densities, viscosities, and refractive indices of the ternary system acetone + ethanol + 2,2,4-trimethylpentane at T = 298.15 K and the binary systems acetone + ethanol, acetone + 2,2,4-trimethylpentane, and ethanol + 2,2,4-trimethylpentane were measured at T = (288.15, 298.15, and 308.15) K and atmospheric pressure over the whole composition range. Densities were determined using a vibrating-tube density meter. Viscosities were measured with an automatic Ubbelohde capillary viscometer. Refractive indices were measured using a digital Abbe-type refractometer. Excess molar volumes V-E, deviations in the viscosity from the mole fraction average Delta eta, and deviations in the refractive index from the volume fraction average Delta n(D) for the mixtures were derived from experimental data. The binary and ternary data of V-E, Delta eta, and Delta n(D) were correlated with liquid composition by using the Redlich-Kister and Cibulka equations.