The present Letter deals with the theoretical investigations of the o-chloranil/aniline complex in gas phase employing ab initio and time-dependent density functional theory methods. The dipole moment vector is directed from aniline to the o-chloranil in o-chloranil/aniline complex. The two O atoms of o-chloranil are found to be oriented towards the -NH2 group of aniline and C=O bond length increases upon complexation with aniline. The charge transfer (CT) transition energy of the o-chloranil/aniline complex corroborates fairly well with the reported experimental value. Frontier molecular orbital calculations reveal a strong propensity of photo-induced electron transfer in o-chloranil/aniline CT complex. (C) 2007 Elsevier B.V. All rights reserved.