What contribution did the Québécois missionary effort bring to the reception of Vatican II in Québec? To answer that, this paper focuses on the experience of members of four missionary institutes founded in Québec: the Missionnaires de l'Immaculée-Conception, the Missionnaires de Notre-Dame des Anges, the Société des Missions étrangères du Québec, and the Missionnaires du Christ-Roi, between 1945 and 1962. This paper analyses the missionaries' preconciliar experience of cultural and religious difference, and shows how it contributed to the emergence of a changing perspective on Christianity, the Church, and mission. Based on interviews conducted with missionaries, the institutes' archives, and secondary sources, this paper argues that parallels exist between shifts in the missionary field with respect to lay people, the local church, cultural and religious differences, and the way the Québec Church prepared itself for Vatican II. [ABSTRACT FROM AUTHOR]