In this work, Functionalized Carbon nanotubes (FCNTs) supported hybrid catalysts including Pt, Fe and Ni nanoparticles were prepared and further used as an electrocatalytic electrode for Proton Exchange Membrane Fuel Cell (PEMFC) cathode. In this regard, various ratios of nitric acid/sulfuric acid were tested for functionalization of CNTs. The ethylene glycol reduction method was applied to deposit the hybrid electrocatalyst nanoparticles on FCNTs. It was revealed that the combination of FCNTs, as the support catalyst, with hybrid platinum and transition metals, accelerated the oxygen reduction reaction (ORR) by passing through the four-electron pathway which was due to the high crystallinity and aspect ratio, low defect density and unique electrical conductivity of CNTs and Pt-transition metals alloys. As a result, the power density profoundly enhanced (up to 237%) while the charge transfer resistance reduced, compared to Pt–C 10%wt commercial catalyst. This study demonstrated the excellent performance of FCNTs decorated Pt–Ni–Fe electrocatalyst can be considered as a good candidate for the future of the catalyst layer in PEMFC.