Polls throughout the country and at consulates opened at 8 a.m. for nine hours to elect a new president, 54 state senators, 27 state governors, as well as 531 federal and state deputies, the BBC said.
President Luiz Inacio Lula da Silva, known as Lula, of the Workers Party must step down after two terms under the constitution. His 62-year-old chief of staff since 2005, Dilma Rousseff, is running to replace him and Lula has campaigned strongly on her behalf, the report said.
Her chief rival is Jose Serra of the Social Democratic Party, considered to be center-rightist.
To avoid a run-off presidential vote Oct. 31, the winner must have at least 50 percent of the vote. Two national newspaper polls each gave Rousseff at least 50 percent and 31 percent to Serra, the report said.
Two other presidential candidates from the Green Party and the Socialism and Freedom Party were trailing far behind, polls showed.