Based on the unique electronic properties and high surface area of carbon nanotubes as well as the similar electronegativity of sulfur and carbon, a novel electrocatalyst for the oxygen reduction reaction (ORR) was fabricated by directly annealing oxidized carbon nanotubes and p-benzenedithiol in nitrogen. The structural and chemical properties of the resulting sulfur-doped carbon nanotubes (pSCNTs) were investigated using transmission electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy. The catalytic activity of the pSCNTs towards ORR in alkaline medium was evaluated using rotating ring disk electrode voltammetry. The as-synthesized pSCNT-900 (annealed at 900 degrees C) exhibits excellent electrochemical performance towards ORR with an onset potential of -0.082 V (vs Ag/AgCl), a high kinetic current density of 34.6 mA cm(-2) at -0.35 V), a dominant four-electron transfer mechanism (n = 3.71 at -0.35 V), as well as excellent methanol tolerance and durability. The results obtained are significant for the development of S-doped carbon-based catalysts for alkaline fuel cells. (C) 2015 Elsevier Ltd. All rights reserved.