Measurements of the apparent cation transference number of a solid polymer electrolyte by a voltammetric technique are compared with results from the steady-state dc polarization method. The combination of measurements made at a microelectrode and at a macroelectrode, performed in the absence of supporting electrolyte, yields both the apparent transference number theta, and the salt diffusion coefficient D. Lithium cationic transference numbers in a series of macroscopically solid gels were determined as a function of salt concentration.