Rationally designing the composition and structure of metallic nanoparticles/reduced graphene oxide hybrids is highly important for synthesizing active electrocatalysts. Herein, we report a one-step method to efficiently synthesize dendritic bimetallic PtPd nanoparticles on reduced graphene oxide (DPtPd/rGO) in aqueous solution at room temperature. The proposed synthesis is performed by a simple sonication treatment of an aqueous reactive mixture containing K2PtCl4, Na2PdCl4, Pluronic F127 and ascorbic acid. This method is greatly simplified compared to the traditional multi-step-seeded growth or other hydrothermal syntheses. The as-made DPtPd/rGO hybrid consists in spatially and locally separated dendritic PtPd nanoparticles well-dispersed on the surface of rGO and is an active catalyst for methanol oxidation and oxygen reduction reactions. The proposed strategy is an effective method to directly fabricate metals/rGO hybrids for electrocatalytic applications. (C) 2015 Elsevier Ltd. All rights reserved.