Bimetallic nanostructures represent effective electrocatalysts towards a number of important reactions. In this work, carbon-supported palladium-tungsten alloy nanoparticles with a quasi-tungsten core@palladium shell structure (W@Pd/C) were prepared by galvanic replacement reaction of amorphous tungsten nanoparticles with Pd(II) at different temperatures (0, 25 and 50 C), and exhibited apparent electrocatalytic activity towards ethanol oxidation reaction (EOR). For the sample prepared at 0 C, large amorphous tungsten nanoparticles were etched off and much smaller W@Pd nanoparticles were formed and dispersed rather evenly on the carbon surface; whereas at higher reaction temperatures (25 and 50 C), agglomeration of the W@Pd nanoparticles became apparent. The structures of the obtained samples were characterized by (scanning) transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and electrochemical methods. The W@Pd/C sample prepared at 0 C was found to exhibit the best electrocatalytic activity towards EOR among the series, with a mass activity (9535.5 mA mg_Pd^(-1)) and stability that is over three times better than that of commercial Pd/C.