Whether private parties and NGOs should participate in the WTO system has recently become one of the most contentious issues in trade law and policy. However, this debate proceeds from the implicit - but mistaken - assumption that these entities currently do not participate in the system. While, as a formal matter, WTO 'legislative' and dispute resolution systems are open only to state actors, in fact private parties already participate extensively in WTO processes. Through discussion of several WTO disputes, including the Kodak-Fuji dispute, this paper demonstrates how the current debate substantially understates the considerable roles that NGOs already play in disputes submitted to the WTO. The claims here are largely positive and descriptive, rather than normative. By identifying and clarifying the roles that private parties currently play, I hope to close the increasing gulf between academic debate and WTO practice, and move the debate over NGO participation to a more fruitful series of inquiries. To this end, I argue that the controversy over NGO participation at the WTO can be understood as a particular instantiation of a larger debate over the roles of non-state actors in the international legal system.