Electron impact ionization of toluene is studied using mass spectrometry. Cross-sections for the formation of molecular ions and ionic fragments are measured between 10 and 78 eV with a total cross-section of 1.5 x 10(-15) cm(2) towards 60 eV. C7H8+ and C7H7+ contribute to below 25 eV. Four ionic fragments: C5H5+, C4H5+, C5H3+ 75% of the total cross-section at 78 eV. The molecular ion is the most abundant 5 3 3 and C3H3+, are detected above 20 eV. Enthalpy considerations can lead to think that C5H5+ is issued directly from the molecular ion, whereas the three other species result from two step pathways. (c) 2006 Elsevier B.V. All rights reserved.