The electrolytic conductances of tetrabutylammonium tetraphenylborate in a number of propylene carbonate + acetonitrile mixtures at (25, 30, and 35) degrees C are reported. The limiting molar conductances, association constants, and distance of closest approach of ions are evaluated by means of the Lee-Wheaten equation. Gilkerson’s solvent-solute interaction energy term is calculated. Values of the Walden product are also reported.