The ability to engineer the composition and structure of nanoalloy catalysts is important for developing active, robust and low-cost catalysts for fuel cell applications. The recognition of the importance of structural and chemical alloying effects of nanoalloy particles on the electrocatalytic properties has been an important driving force for the exploration of various binary and ternary platinum-based alloy catalysts. In comparison with the extensive studies of binary alloy catalysts for oxygen reduction reaction, the exploration of ternary nanoalloy catalysts in the past few years has led to many intriguing discoveries in terms of enhanced catalytic activities. In this article, we highlight recent progress of our work in the synthesis, processing and electrochemical characterization of molecularly-capped ternary nanoalloy catalysts, focusing on the enhanced electrocatalytic activity of Pt-based ternary nanoalloy catalysts for oxygen reduction reaction in fuel cells. Selected examples of ternary nanoparticle catalysts for electrocatalytic oxygen reduction reaction will be discussed. While important insights have been gained from studies of detailed structural aspects based a variety of techniques, this report summarizes some of the major findings in the studies of the electrochemical and electrocatalytic properties of the ternary nanoalloys to highlight the importance of ternary composition for the design and preparation of electrocatalysts. (c) 2012 Elsevier B.V. All rights reserved.