Using a novel formulation of the Hartree-Fock approximation with the flexible potential morphing method we calculate the effective band gap of InAs nanorods as well as the binding and correlation energies of neutral and charged excitons confined in such nanostructures. Our results indicate very good agreement with recent experimental data as regards the behavior of the effective band a gap with the nanorod's length and suggest stability conditions for the neutral and charged excitons. (C) 2005 Elsevier B.V. All rights reserved.