The US-educated son of a top aide to Paraguay's late dictator is favorite to win Sunday's presidential election in one of Latin America's poorest countries.
Opinion polls give Mario Abdo Benitez of the ruling conservative Colorado party a clear lead over his centrist opponent, Efrain Alegre, in a two-horse race to succeed outgoing conservative President Horacio Cartes.
Polling stations opened at 7:00 am (1100 GMT) and are due to close at 4:00 pm.
Landlocked Paraguay -- sandwiched between Bolivia, Argentina and Brazil -- has enjoyed consistent economic growth under tobacco magnate Cartes, but has failed to shrug off persistent poverty, corruption and drug trafficking.
It remains a land of contrasts, still marked by the 1954-1989 dictatorship of General Alfredo Stroessner.
However, a new generation of voter among the electorate of 4.2 million -- born after the dictatorship responsible for the deaths or disappearances of up to 3,000 people -- seems ready to turn the page.
Forty-three percent of the population is aged between 18 and 34.
Polls in recent weeks have given Abdo Benitez, the twice-divorced son of Stroessner's personal secretary, a lead of 20 points ahead of 55-year-old Alegre in the race to succeed Cartes.
However, the latest opinion polls predict a neck and neck finish and predicate an Abdo Benitez win on a turnout of less than 70 percent.
Tobacco magnate Cartes kept Paraguay on course for year-on-year growth of about 4.0 percent on an economy based on exports of soybeans, meat and electricity.
But there has been little progress in alleviating poverty that has remained stubbornly at 26.4 percent and corruption, with Paraguay languishing 135th out of 180 countries ranked by Transparency International.
"If Benitez loses, it will be a vote of sanction against Cartes, who has presided over a government of exclusion. People are reacting with weariness," pollsters Sneard told AFP.
Abdo Benitez, who goes by the nickname "Marito", has pledged to reform the judicial system to render it less prone to corruption, but to maintain Cartes' economic policy.
Alegre, the outsider at the head of the centrist GANAR alliance, has offered free health care for the poor and to slash the cost of electricity to stimulate investment and jobs.
The two adversaries agree on one point: they oppose the legalization of abortion and gay marriage in the deeply conservative Catholic country.
"I am for life. I am against abortion and its decriminalization, in any case. Personally, I believe that nobody can take the place of God to decide on the life or death of a person," Alegre told AFP in an interview.
In addition to choosing a president, the electorate will also elect a new parliament and governors of the country's 17 departments.
Electing Abdo Benitez despite his father's links with the dictatorship would confirm if Paraguayans have turned the page on the darkest chapter of their recent history.
"Paraguayan society is changing faster than its political elites, and there is a generation, which is becoming increasingly influential, which does not really remember the undemocratic regime. This is a first in the history of Paraguay," said Oliver Stuenkel, professor of international relations at the Getulio Vargas foundation in Sao Paulo, writing in Americas Quarterly.
The odds are stacked in Abdo Benitez's favor: The only time the country had a president who did not come from the Colorado party was in 2008-2012 when former Catholic bishop Fernando Lugo ruled.