Chile's 1980 constitution was drafted under a Junta led by General Augusto Pinochet which had seized power in a 1973 coup that overthrew the government of President Salvadore Allende. Shortly after seizing power, the Junta announced that the country's 1925 constitution, though nominally in force, would be subordinate to the "imperatives of the state" as defined by the Junta. Shortly thereafter in 1973, the Junta appointed an advisory Constituent Commission, subordinate to the Ministry of Justice but relatively independent from the Junta, that was comprised of civilian lawyers. The Junta made it clear that it exercised "Supreme Command" of executive, legislative and constituent powers. The Supreme Court remained independent, but decided not get involved in human rights cases. The Armed Forces, not the courts, prosecuted "political offenses." On July 24, 1974, the Supreme Court ruled out modification of the 1925 Constitution arguing that decree laws contravened the constitution. If enacted without any indication that they are constitutional amendments, the court asserted, they would be struck down when challenged in live cases. Nonetheless, in 1975, Pinochet announced that several Acts would be promulgated.
In July 1980, the Council of State presented its recommendations to the President. The Junta then hammered out the final text.
Without any public education campaign or public discussion the new constitution was ratified by 67% of those voting in a plebiscite on September 11, 1980. Chileans and resident foreigners over the age of 18 had only to present their national identity card and could vote at any polling place. Blank ballots counted as "yes." The vote was deemed fraudulent by many. The constitution was placed into effect on March 11, 1981.