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Abstract: The development of cheaper electrocatalysts for fuel cells is an important research area. This work proposes a new, simpler and low-cost approach to develop nanostructured silver electrocatalysts by using natural cellulose as a template. Silver was deposited by reduction of Ag complexes on the surface of cellulose fibers, followed by heat removal of the template to create self-standing nanostructured silver fibers (NSSFs). X-Ray diffraction (XRD) showed fcc silver phase and X-Ray photoelectron spectroscopy (XPS) demonstrated that the surface was partially oxidized. The morphology of the fibers consisted of 50 nm nanoparticles as the building blocks, and they possessed a specific surface area of about 25 m2/g, which is sufficiently high for electrocatalytic applications. The NSSFs were incorporated in a graphite composite electrode. The resulting modified electrode displayed a good electrocatalytic activity for the reduction of dissolved oxygen in basic media. In an O2-saturated 0.1 M KOH solution, the overpotential to initiate the oxygen reduction reaction reduced and the limiting current increased by increasing the relative amount of silver fibers from 0 to 5 wt%. [Copyright &y& Elsevier]