Some perfluoroalkylolefins are shown to undergo electrochemical one-electron reduction to the corresponding radical anions at potential values which strongly depend on the structure of the substituents. In these cases the voltammetric reduction peak is chemically reversible, and a further one-electron transfer, affording the corresponding dianions, is detected at more negative potentials. For these substrates, at appropriate temperatures, the free radical anions are stable enough to be accumulated by macroscale electrolysis and investigated by EPR. The spectra are characterized by fairly large hyperfine couplings of 19F in a, ß, and y positions relative to the v carbon centers and by line width effects due to restricted rotations of the perfluoroalkyl groups around the CC single bonds. The case of tetrakis (trifluoromethyl) ethylene has been analyzed in detail, and it is concluded that the rotation motion of the four trifluoromethyl groups should be in part correlated.