A persistent perfluoroalkyl radical (PPFR), perfluoro-3-ethyl-2,4-dimethyl-3-pentyl, is shown to be a good source of CF3 radicals and a useful radical capable of initiating the polymerization of vinylidene fluoride (VDF). NMR characterizations of the resulting PVDF homopolymers showed that polymerization of VDF was exclusively initiated by CF3 radicals. The addition of CF3 radical onto VDF was regioselective leading to CF3-CH2-CF2-PVDF and the CF3 end-group acted as an efficient label to assess the molecular weights by 19F NMR spectroscopy. Various [PPFR]0/[VDF]0 initial molar ratios lead to CF3PVDFCF3 of different molecular weights. When that ratio decreased, both the molecular weights and the thermostability of these PVDFs increased, showing less defects of chaining and higher crystallinity.