But deputy party leader Tomislav Nikolic has already conceded he will not be able to form a government. Instead, the current reformist coalition appears better positioned to remain in power -- although tough negotiations lie ahead.
The vote was the first since the breakup of Serbia's union with Montenegro in 2006. And it shows that despite years of international isolation, war, and economic hardship, nationalist rhetoric still appeals to a large segment of Serbia's embittered population.
The Serbian Radical Party, whose former leader Vojislav Seselj is now on trial at The Hague, has been the standard bearer of that nationalism.
Current leader Nikolic declared victory overnight, but admitted that with 81 seats out of 250 in the new parliament -- and no major coalition allies -- he will not be in a position to govern. He warned that pro-Western parties, however, will have a tough time putting together a coalition.
"We will not have the opportunity to form a government," Nikolic said. "But it is obvious that those who repeatedly said they didn't want to deal with us will now have a problem figuring out who they will deal with."
The pro-reform camp took some encouragement from the fact that President Boris Tadic's Western-backed Democratic Party came in second place, with nearly 23 percent of the vote, in its best-electoral result ever.
Analysts note
that most Serbian voters are less concerned with nationalism than with bread-and-butter issues such as jobs and restoring relations with Europe.
Tadic appears best placed to assemble a coalition that would include Prime Minister Vojislav Kostunica's Democratic Party of Serbia, which came in third, as well as smaller reformist groups.
Tough Times Ahead
"If you put together Tadic's Democratic Party and Kostunica's Democratic Party of Serbia and the liberal reformers in the G17 Plus group, you get 132 seats out of 250, which is a clear majority," said RFE/RL Balkans analyst Patrick Moore. "And you could possibly add to that 14 seats from the ultra-reforming Liberal Democrats and seven seats that are held by ethnic minorities, so that would be a very comfortable majority, if it could be put together."
On a personal level, however, Tadic and Kostunica have long been at odds. Will Tadic overlook those differences and back Kostunica to remain as prime minister or will he nominate someone else? There will be much backroom bargaining in the days ahead.
Although Tadic appears more outwardly pro-Western and Kostunica retains his nationalist allegiances, analysts say both politicians must above all think pragmatically.
The EU froze talks on closer ties with Serbia in May 2006 because of Belgrade's reluctance to arrest fugitive war crimes suspects.
Until those ties are unfrozen, Serbia cannot expect to make much economic progress.
EU foreign policy chief Javier Solana made it clear again today that Europe wants to see a reformist coalition in Serbia.
"The majority of [voters] have voted for forces which are democratic and pro-European, and we hope very much that there will be a speedy formation of [a] government," Solana said.
The Kosovo Problem
The Kosovo issue may, of course, complicate those efforts. No major politicians in Serbia -- whether reformist or nationalist -- publicly supports Kosovo's independence.
The province has been under UN control since the summer of 1999 and later this week, UN envoy Martti Ahtisaari is expected to propose his recommendations for Kosovo -- which could include independence.
If that happens, managing the Serbian nationalist backlash while at the same time pleasing the EU will prove a tough challenge for Belgrade reformist politicians.
To view RFE/RL's archive of coverage related to EU expansion, click here .