Proline (Pro, H9C4NO2) is an imino-acid implicated in the structure of proteins. Here, we show the ability of low-energy (< 12 eV) electrons, predominantly produced at the very early time along the ionization tracks, to effectively decompose the imino-acid via dissociative electron attachment. The decomposition of Pro produces various negatively charged fragments attributed to dehydrogenated proline (Pro-H)(-), glycil-yl(-), (HCO2)(-), CN-, OH- and O- ions and their respective neutral counterparts. The present information contributes to a better comprehension of the alteration of proteins induced by radiation. (C) 2004 Published by Elsevier B.V.