In this Letter, we use the perturbed matrix method, in combination with molecular dynamics and statistical mechanics, in order to describe in details the electric field induced intramolecular charge transfer (ICT) in two pi-conjugated oligomers of nanotechnological interest. Results show a relevant relationship between the extent of ICT and molecular conformation, pointing out the highly non-linear charge transfer field response. (c) 2006 Elsevier B.V. All rights reserved.