The electrolytic conductance behavior of certain univalent electrolytes, viz., tetrabutylammonium tetraphenylborate, tetrabutylammonium halides, tetrabutylammonium perchlorate, tetraethylammonium perchlorate, tetraethylammonium iodide, tetraethylammonium 2,5-dichlorobenzenesulfonate, tetraethylammonium p-toluenesulfonate, tetramethylammonium iodide, sodium tetraphenylborate, sodium iodide, and potassium iodide in 80 mass % propylene carbonate + p-xylene, was studied. The conductance data were analyzed by the Fuoss conductance-concentration equation. The ionic conductivities have been calculated using the Lambda(0) value of tetrabutylammonium tetraphenylborate as a reference value that is independent of solvent. The association constants and cosphere diameters for the above electrolytes are reported. The variations of ionic conductivities are explained in terms of viscosity, the Stokes radii in some specific cases, and specific ion-solvent interactions.