(Reuters) Argentines head to the polls on Sunday to choose a new president to succeed Nestor Kirchner, who has governed for the past four years.
Opinion polls suggest the president's wife, Cristina Fernandez de Kirchner, will be victorious in the first round.
Her main rivals are the former beauty queen, Elisa Carrio, and Mr Kirchner's ex-Economy Minister Roberto Lavagna.
Voters will also elect eight provincial governors, a third of the Senate and about half of the Chamber of Deputies.
Polls will open in the compulsory ballot at 0900 (1200 GMT) on Sunday and end at 1800 (2100 GMT). There are some 27 million people eligible to vote.
The economy and rising crime have been the two main issues in campaigning.
Just a few months ago, Mr Kirchner was riding high in the opinion polls and looked set to continue for a second four-year term as Argentina's president.
However, it was announced in July that his wife, Cristina, the senator for Buenos Aires province, would stand in his place. No explanation has been given.
The president's wife has consistently led the opinion polls since her campaign began, and most analysts say she will get enough votes in the first round to avoid a second.
To win outright in the first round, a candidate needs to obtain either 45% of the vote, or 40% if they are 10 percentage points ahead of their nearest rival.
If Mrs Kirchner wins, she will be the first woman elected president of Argentina.