This book analyses whether, and how, equity and equitable principles can be employed as juridical tools in the legal reasoning of judges and lawyers in World Trade Organization (WTO) disputes where there is interaction between norms derived from the multilateral trade regime and other international legal regimes. Bringing the literature on equity and equitable principles in international law up to date this book tackles several legal problems which have emerged in WTO dispute settlement practice as well as engaging with the concept of the fragmentation of international law. The book provides an original argument about the role and significance of equity and equitable principles in the debate over fragmentation by providing a coherent methodology for addressing conflicts and overlaps between WTO and non-WTO norms in the context of Dispute Settlement Body proceedings.