The poly(paraphenylenevinylene) PPV, conjugated polymer has been derived from a sulfonium salt precursor by ion beam irradiation. A quadrupole mass spectrometry analysis of the evolved species shows the rapid loss of the HCl and tetrahydrothiophene groups during irradiation with 100 keV Ne + indicating the precursor degradation. Rutherford backscattering spectrometry confirms the reduction of the sulfur and chlorine content in the PPV film, whereas the infrared spectrum shows that the vibration mode at 2940 cm -1 of the sulfonium group has banished for a 2 × 10 16 ion fluence. The appearance of the transvinylene peaks, at 3024 and 965 cm -1 in PPV, indicates the full conversion of the precursor ionto the conjugated polymer for this fluence. The correlation between a narrower optical band gap and (by one order of magnitude) higher conductivity of a film implanted with Na + ions with respect to a Ne + irradiation shows the doping effect induced by an implantation with electronically active species. We conclude to the simultaneous conversion and doping of the PPV polymer upon ion implantation.