Photon stimulated ion desorption (PSID) spectra were determined around the Cl 2p edge for poly(vinyl chloride) (PVC), using synchrotron radiation and a time-of-flight mass spectrometer (TOF-MS). Partial ion yields have been determined for the main fragments as a function of the photon energy. A striking demonstration of photon energy dependence is observed for the Cl+ ion around the Cl 2p edge. (C) 2004 Elsevier B.V. All rights reserved.