We report a general bottom-up synthetic methodology to epitaxially grow 3-nm-thick single-crystalline PdPt bimetallic nanowires using amphiphilic dioctadecyldimethylarnmonium chloride as the surfactant template. Mechanistic studies show that the existence of Pd element is critical in the synthesis of bimetallic PdPt nanowires with controllable atomic ratios. Due to synergistic effect of anisotropic single-crystalline ultrathin one-dimensional nanostructures and bimetallic elemental compositions, the resulting PdPt nanowires exhibit superior electrocatalytic activity and stability towards the hydrogen evolution reaction (HER). Among them, bimetallic Pd86Pt14 nanowires show the best HER activity with a small overpotential of only 0.8 mV in acidic media at a current density of 10 mA/cm(2) (12.8 mV positive than that of commercial Pt nanoparticles), and excellent stability with only 4.6% loss in activity after current-time chronoamperometric responses for 26 h. This surfactant template-directing approach opens a general method for precise control of anisotropic nanostructures in diverse bimetallic nanomaterials for the high-performance electrocatalysts.