Daniel Des Aulniers studied at the Université Laval and was admitted to the Barreau du Québec in 1976.  He chiefly practices business and corporate law, specializing in bankruptcies and insolvency.  He also practices civil law.

  
Mr. Des Aulniers is a member of the Canadian Bar Association and the Chambre de commerce et Industrie du Québec Métropolitain.  He also administers corporations with social and humanitarian objectives.
 
He has delivered several speeches on bankruptcy and insolvency on behalf of the Canadian Bar Association, the Groupement Québécois d'entreprises and the Canadian Insolvency Association. He has delivered speeches on business law on behalf of the Association Québécoise des transporteurs aériens, and on public law on behalf of the Association of Young Political Leaders in Bonn, Germany. (1981–1986).