In Brazil, the office of Mayor is the head of government of the smallest territorial unit — the município — and holds actual executive powers of local administration. In Portuguese, its title is called prefeito.
Until 1982, Brazilian mayors were usually elected by the local municipality population, except 1) state capitals, 2) international border towns, and 3) "national security zones" (which included important mining places). After the 1988 Constitution, all mayors in the nation are directly elected every four years.
The capital (Brasília), however, is governed by the Governor of the Federal District, who is not a mayor per se, but rather shares the same status as state governors.
In Brazil, mayors of largest cities, such as Rio de Janeiro and São Paulo, have considerable influence in national politics, and are usually potential candidates to presidency.