An effort to develop an electrochemically smaller and well-dispersed catalytic material on a high surface area carbon material is required for fuel cell applications. In terms of pure metal catalysts, platinum has been the most common catalyst used in fuel cells. Here, a rotating disk-slurry electrode (RoDSE) technique is presented as a unique method to electrochemically prepare bulk Pt/carbon nanocatalysts material avoiding a constant contact of the carbon support to an electrode surface during the electrodeposition process. The Pt/carbon nanocatalyst was prepared by using a slurry solution that was saturated with functionalized Vulcan-XC-72R in 0.10 M H2SO4. The platinum precursor added to the slurry solution was K2PtCl6. The electrochemically prepared Pt/C catalyst was characterized by using transmission electron micrographs, X-ray diffraction, X-ray fluorescence, thermogravimetric analysis, and X-ray photoelectron spectroscopy techniques. Electrochemical experiments were carried out to examine their activity and stability compared to a commercial ETEK Pt/C catalyst. The RoDSE nanocatalyst that contained half of the weight percent of platinum (11%) compared to the commercial 22% Pt/Vulcan XC-72R catalyst showed similar electrochemical responses to the commercial catalyst. These results demonstrate that the use of the RoDSE technique is an effective method to prepare bulk quantities of carbon-supported platinum nanocatalysts for fuel cell applications via an electrochemical route. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3489948] All rights reserved.