The exploration of efficient nanocatalysts with high activity and stability toward the oxygen reduction reaction (ORR) is extremely important for the advancement of fuel cells but still remains challenging. The capability of rational synthesis of one-dimensional ultrathin Pt-based nanowires could effectively address this issue. Herein, we demonstrate a facile one-pot hydrothermal synthesis of uniform ultrathin Pd-Pt alloy nanowires with a high yield. The judicious adoption of NaI as a structure-directing agent and Pluronic F127 as a stabilizing agent is crucial for the formation of the ultrathin Pd-Pt nanowires by manipulating the reaction kinetics. Due to the bimetallic synergetic effect and unique structural advantage, the as-prepared Pd-Pt alloy ultrathin nanowires outperform commercial Pd black and Pt black catalysts toward ORR, with much improved activity and stability. We expect that this work will provide a promising strategy for the development of efficient ORR electrocatalysts and can also be extendable for the preparation of other one-dimensional bimetallic nanostructures. Copyright (C) 2016, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.