Intimidation of arbitrators in investment law is a rarely approached but significant threat to the legitimacy of the arbitral process. The article discusses the legal basis in the relevant treaties and conventions, as well as general principles of law, in regulating the behaviour and maintaining the impartiality and independence of arbitrators. With consideration of the distinct sources of intimidation, the article pursues the complicated reality of fairly approaching intimidation that comes from different actors, in particular from one of the parties. Respecting that dismissal of a compromised arbitrator may be in line with the desires of the actor and that the arbitrators typically take the decision on whether to dismiss, alternative methods for ensuring a fair trial and due process are assessed. The article concludes by looking with a critical eye at the current structure of the system and the possibility of unknown intimidations.