The conductance behavior of potassium iodide, potassium perchlorate, potassium methanesulfonate, potassium 2,5-dichlorobenzenesulfonate, silver perchlorate, silver picrate, tetrabutylammonium tetraphenylboride, tetrabutylammonium iodide, ferricinium picrate, and perchloric acid has been studied in a 20 mass % propylene carbonate + ethylene carbonate mixture. The conductance results have been fitted to the Fuoss (1978) conductance-concentration equation using the Fuoss computer program. Values of the limiting molar conductance (lambda0), association constant (K(A)), and cosphere diameter (R) have been obtained. The limiting ionic mobilities of the systems studied have been reported based on tetrabutylammonium tetraphenylboride as the reference electrolyte.