The Federal Legislative Power is exercised by the National Congress, which is made up of two Legislative Houses: the Chamber of Deputies and the Federal Senate. It can therefore be said that the Federal Legislative Branch is bicameral. The typical functions of the Legislative Branch are to legislate and supervise.

The functions of the Federal Senate are exercised by the senators of the Republic, who are elected according to the majority principle to represent the states and the Federal District. Each state and the Federal District elect three senators for an eight-year term. Representation is renewed every four years, alternately by one and two thirds. Each senator is elected with two alternates.