This Practice Note sets out the how a party to arbitration may challenge the jurisdiction of an arbitrator or tribunal in Canada and the position in relation to anti-suit injunctions. It deals with the use of the 1985 UNCITRAL Model Law in Canadian law, and the amended version adopted in 2006, the position in relation to provincial, territorial and federal international arbitration legislation, judicial intervention and the process for making a challenge. It also covers the granting of anti-suit injunctions, the staying of proceedings in Canada, the courts’ approach and the duration, timing and costs of the procedure.