Densities (ρ), viscosities (η), and ultrasonic velocities (u) through solutions of lithium nitrate in dimethylsulphoxide (DMSO) + ethanol mixtures have been measured as a function of electrolyte concentration and temperature. The suitability of various polynomial equations in reproducing the experimental values of ρ, η, anduwas checked for the present system. The adiabatic compressibility (β), intermolecular free length (Lf), relative association (RA), specific acoustic impedance (Z), molar sound velocity (Rm), enthalpy (ΔH*) and entropy (ΔS*) of activation of viscous flow have been computed. The results are explained in terms of solvent-solvent and ion-solvent interactions.