Ru-Pd bimetallic nanocrystals are successfully synthesized via a facile polyol co-reduction method. The resulting nanocrystals show spheres, triangular nanoplates, decahedra, nanorods, and irregular shapes. A combination of Pd-II and Ru-II precursors tends to yield Ru-Pd bimetallic nanocrystals of higher shape monodispersity than those from Pd-II and Ru-II precursors. The mole ratio between Ru and Pd components in the precursor solution also plays a key role in determining the size/shape distribution of the nano crystals, with higher Pd/Ru ratios generating products of more uniform size. Elemental analyses and electron microscopy studies suggest that the obtained nanocrystals have alloyed structures over the full composition space and that they form through either monomer addition or coalescence mechanisms. (C) 2016 Elsevier B.V. All rights reserved.