Former ultra-nationalist allies of Slobodan Milosevic may return to power in Serbia, 12 years after the late Balkan strongman was ousted by pro-Western forces seeking European Union membership.
The first-round vote for president, and votes for a 250-seat national assembly and local councils pit pro-EU democrats against nationalists who have gained in popularity with the EU's own economic troubles, which have dimmed the bloc's allure for many Serbs.
The two leading contenders are the Democratic Party of Boris Tadic - who had been president until he resigned so the triple vote could be held together - and Milosevic's former ally Tomislav Nikolic, whose right-wing populist Serbian Progressive Party has Russia's support, though he has lately claimed a shift toward the EU.
The eventual outcome could determine whether Serbia abides by EU-demanded economic and social reforms after being an isolated pariah nation under Milosevic in the 1990s because of his warmongering - or turns to its traditional Slavic ally Russia instead.
It also will show whether Serbia continues to reconcile with its neighbours and wartime foes of the Balkan conflicts, including the former province of Kosovo, which declared independence in 2008.
Recent polls have suggested that the pro-EU camp slightly trails the nationalist bloc in the parliamentary race, but with the democrats having better chances of persuading smaller parties to form the next coalition government - just as they did after the previous elections four years ago.
A presidential runoff is expected on May 20, as both Mr Tadic and Mr Nikolic are unlikely to get more than 50% of the first round vote that includes 12 candidates.
In March, Mr Tadic led Serbia's bid to gain EU candidate status, which was conditional on the arrests of fugitive war crimes suspects Ratko Mladic and Radovan Karadzic. His government turned over the two wartime Bosnian Serb leaders to a UN tribunal in the Netherlands to face genocide charges for their part in the 1992-95 Bosnian war.
However, Mr Tadic's popularity among Serbs has fallen because of the country's economic downturn. Faced with the global financial crisis, which slowed down much needed foreign investments, his government has seen massive job losses and plummeting living standards.
Mr Nikolic has gained the support among voters for criticising widespread social injustice and corruption, and for promising jobs, financial security and billions of dollars in foreign investments if he and his party win the elections.