This Letter describes a simple, aqueous-phase route to the synthesis of Pd-Rh bimetallic nanodendrites consisting of Rh branches anchored to a Pd nanocrystal core. Palladium nanocrystals with various shapes, including truncated octahedron, cube, octahedron, and thin plate, have all been successfully employed as seeds to grow Rh branches via the reduction of Na3RhCl6 with L-ascorbic acid in an aqueous solution. The degree of Rh branching could be controlled by varying the concentration of Na3RhCl6 involved in a synthesis. Electron microscopy analysis revealed that growth of Rh branches proceeded via attachment of small Rh particles that had been formed via homogeneous nucleation in solution. (C) 2010 Elsevier B. V. All rights reserved.