The objective of this work is to propose a novel approach to prepare highly charged nanoaerosol particles. The nanoparticles are first enlarged by condensation of solvent vapor in a mixing-type particle magnifier (PM); the enlarged droplets are then charged by a corona ionizer; the charged droplets are finally dried to return the nuclei to their original size. Experiments were performed with neutralized nanoparticles generated by electrospray of colloidal suspensions, or by the evaporation-condensation method. Average particle charge obtained by this method was found to be approximately proportional to the D-1.9(.p). (C) 2005 Elsevier Ltd. All rights reserved.