This work reports a theoretical investigation about the structural and electronic properties of polymers constituted by pyrrole and N-hydroxymethylpyrrole in both neutral and p-doped states. Ab initio quantum mechanical calculations were performed on neutral and positively charged oligomers to evaluate the bond length alternation pattern in the pi-system, the molecular conformation, the pi-pi* transition energies and the ionization potential. Results, which have been extrapolated to infinite polymer chains, allow analyze the influence of N-hydroxyalkylation of polypyrrole on these properties. (c) 2006 Elsevier Ltd. All rights reserved.