A survey of the evolution of the jurisprudence of the Supreme Court of Canada in matters of grievance arbitration. From 1975 to 1986 the Court of Canada establisheda policy supportive of the grievance arbitration process. Professor Nadeau reviews the seminal Court decisions, establishing a policy of deference to labor arbitrators’ rulings on collective bargaining agreements and also on external law when necessary to deal with the grievance. And he examines the Court’s rulings since 1986, and the affects of the later rulings on the jurisdiction of and the Court’s deference to arbitrators. In Parry Sound (2003), the Court ruling that even where there is no alleged violation of one of the express provisions of a collective agreement, a grievance arbitrator nevertheless has the jurisdiction to interpret and apply statutes governing human rights.