The electrochemical reduction of oxygen on highly oriented pyrolytic graphite (HOPG) electrodes coated with multiwalled carbon nanotubes (MWCNTs) was investigated in alkaline media using the rotating disk electrode (RDE) technique. A hydrodynamic method was employed for the deposition of nanotubes onto HOPG. The surface morphology of the MWCNT-modified HOPG electrodes was examined by atomic force microscopy. RDE studies indicate that the MWCNT/HOPG electrodes reveal a remarkable electrocatalytic activity toward O-2 reduction, and the surface morphology of the modified electrodes showed that the distribution of nanotubes on the HOPG surface was rather uniform and no essential agglomeration was evident.