Herein, we present an ultrasonication-assisted wet-chemical method for facile synthesis of uniform bimetallic AuPt alloy nanodendrites (NDs), using 4-amino-2,6-dihydroxypyrimidine as the structure-directing and dispersing agents, without any template, seed, organic solvent or polymer. The structure, morphology, size, and composition of the as-obtained nanocrystals are examined by a series of characterization techniques. The architectures display remarkable catalytic performances toward oxygen reduction and hydrogen generation in comparison with commercial Pt black and Pt/C catalysts, through the polarization, chronoamperometry, and durability measurements. This is due to the special dendritic nanostructures with rich surface defects, porous features and the synergistic effects between Pt and Au in the alloy. In combination with the simple, easily controllable, and time-saving synthetic strategy, AuPt NDs may find potential applications and shed some light on the construction of other bimetallic nanocatalysts in fuel cells. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.