According to the 2002 census of the National Statistics Institute, Padre Las Casas spans an area of 400.7 km2 (155 sq mi) and has 58,795 inhabitants (29,327 men and 29,468 women). Of these, 33,697 (57.3%) lived in urban areas and 25,098 (42.7%) in rural areas. Between the 1992 and 2002 censuses, the population grew by 26.9% (12,470 persons).
As a commune, Padre Las Casas is a third-level administrative division of Chile administered by a communal council, headed by an alcalde who is directly elected every four years. The 2008-2012 alcalde is Juan Eduardo Delgado Castro. The communal council has the following members: