Michel Décary has pleaded before the courts of all levels, including up to the Supreme Court of Canada, as well as provincial and federal administrative tribunals, domestic arbitration tribunals and commissions of inquiry, in matters involving civil, corporate, and securities law as well as administrative, constitutional and labour law. Michel is a Fellow of the American College of Trial Lawyers, of which he was Regent from 2006 to 2010. Michel also deals with matters involving directors' and officers' liability and has taught at the Corporate Governance College at McGill University's Institute of Corporate Directors (2004–2013) and in the training program offered by Université de Laval's Collège des administrateurs de sociétés (2005–2012). Michel sits (presently and in the past) on the boards of various commercial corporations and non-profit organizations. Michel has been involved in major administrative and constitutional cases, representing the governments of Canada, Québec and New Brunswick, and many businesses.