The globalization of the economy ensures that the number of transnational disputes will continue to rise and find their way to an international arbitral tribunal. International arbitral institutions as well as the International Bar Association have developed standards aimed at helping arbitrators determine what they must disclose to the parties when asked to serve as an arbitrator. This article highlights the similarities and differences in the various disclosure rules and then turns to the views of US courts on disclosure in the context of challenges to awards under the Federal Arbitration Act for "evident partiality" by an arbitrator. Although the disclosure standards have the same helpful aim, they are not worded identically. There are four key differences between them. The first is how to determine whether the arbitrator has to disclose. The second is whose point of view is used to determine the standard. The third is what the arbitrator should disclose. The fourth is whether the arbitrator has a duty to investigate.