This paper examines the practice of archival appraisal in two major archival institutions, from opposite hemispheres and realities: Canada and Brazil. The main objective is to increase knowledge about such an important function for archival practice in the National Archives of these countries. The work covers the theoretical basis used to conduct the appraisal, the main legislation and the instruments used. Finally, the main goal, regardless of the country, is that the practice of appraisal optimizes financial resources and time, reduces the risk of undue destruction of documents and promotes accountability, transparency, and social representation.