This Letter describes the first synthesis of fivefold twinned nanorods and right bipyramids of palladium in an aqueous solution, with ascorbic acid as a reducing agent and in the presence of bromide. Like the silver system, these two types of nanostructures are derived from multiple and single twinned seeds, respectively. The ascorbic acid, bromide, and reaction temperature all play important roles in the synthesis. (C) 2007 Elsevier B.V. All rights reserved.