Studies have been made in the quantitative description of the various ohmic losses present in an ion-exchange fuel cell. Slow electrochemical polarization has been separated from the ohmic losses present in a cell by using a Kordesch-Marko Bridge, and the value of these losses were confirmed by a separate A.C. bridge measurement. Methods for measuring the characteristic resistance of most cells components have been reported. Finally, a method of characterizing the multi-layer reinforced ion-exchange membrane, as made up of a series of characteristic resistances associated with each impregnated ply of reinforcing, is presented. Although data are only approximate, results indicate the usefulness of this concept in predicting reinforced-membrane ohmic resistances.