Because of this disagreement we carried out the measurementsof the size of ethanol aggregates by Zetasizer Nano ZS in the rangeof ethanol mole fraction in which their presence can be expectedon the basis of the surface tension, density and viscosity measure-ments as well as the literature data. It appeared that the notablevalues of the size of alcohol aggregates were obtained at firstapproximation in the range of its mole fraction correspondingto the break points on the surface tension, density and viscos-ity isotherms. From the dynamic light scattering measurementsit appeared that the aggregation of ethanol molecules takes placenot only by the interaction of the hydrogen bonds but also of thehydrophobic ones because ethanol aggregates can include morethan 5 molecules. It also turned out that the ethanol aggregationnumber increased slightly from 5 to 11 molecules (aggregate diameter range: 0.95–1.25 nm) in the range of its mole fraction in whichthe aggregation of its molecules was expected. The aggregationnumber of ethanol agrees with that found in the literature [26].