This chapter examines the WTO Appellate Body, describing the origins and structure of the Appellate Body. The chapter goes step-by-step through the appellate process. It discusses some of the issues that have arisen regarding the scope of appellate review, including the distinction between questions of law and questions of fact; the treatment of municipal law; remand authority; judicial economy; and appeals under Article 11 of the DSU. The chapter provides a detailed explanation of the current crisis in the WTO Appellate Body and describes the efforts that have been made to resolve the impasse, includingg the so-called Walker Process and the MPIA arrangement that has been set up by several Members as a temporary alternative to the Appellate Body.