The Legislative Power is exercised by the National Congress, which is composed of two houses: the Chamber of Deputies (Câmara dos Deputados) and the Federal Senate (Senado Federal).

The number of members in the Chamber of Deputies from each State and the Federal District is proportional to its population. Deputies are elected for four-year terms by direct secret ballot under the system (adopted for all elections for public office) of universal suffrage.

Senate is composed of three Senators from each state and the Federal District, elected for a term of eight years. Senatorial elections are staggered (one-third and then two-thirds) every four years, in elections held concomitantly with those for the Chamber of Deputies.

A Deputy and a Senator can stand for re-election without restriction. There are presently 81 Senators and 513 members of the Chamber of Deputies.