The redox properties of verdazyl radicals are presented using cyclic voltammetry techniques. These radicals can be reversibly reduced as well as oxidized. Electron-donating and -withdrawing substituents have significant effects on the oxidation and reduction potentials as well as the cell potential (E-cell = |E-ox(degrees) - E-red(degrees)|) for these radicals; a correlation between the electron spin distribution and redox properties is developed.