In this work, mechanisms that control the dissociation of Leucine amino-acid by low-energy (< 10 eV) electrons are investigated. At sub-excitation energies, Dissociative Electron Attachment is initiated by a shape resonance, whereas core-excited resonances is involved at higher energies. Under the present conditions, we observe three fragment ions (Leu-H) , (Leu-16 amu) and anion at 42 amu. The (Leu-16) species observed near 1.0 eV and the (m/z) 42 anion produced near 7.8 eV are interpreted to arise from the decomposition of the amino-acid side group. The (Leu-H) anion observed at 1.1 eV is induced by from the fragmentation of the carboxylic group. (C) 2009 Elsevier B. V. All rights reserved.