Enthalpies of mixing, heat capacities, and viscosities of the binary systems involving alcohols (methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and 2-butanol) + olive oil were measured at 298.15 K. The enthalpy was measured in the range of concentrations in which alcohols were miscible with the oils. The highest measured enthalpies of mixing per mole of mixture were (3450 J/ mot) for 2-butanol-olive oil at an alcohol mole fraction of 0.55. Enthalpy of mixing of 2-propanol with sunflower and soybean oil and viscosities of the same mixtures were investigated at 298.15 K. Very similar results were found for the different oils. The mixing of alcohols with oils was strongly endothermic. Viscosities of the same mixtures were measured with a rotational viscometer.