The Social Democrats came second with 22.0 percent, well ahead of the far-right FPO on 16.0 percent and the resurgent Greens on 14.3 percent, the projection showed.
Austrian conservative leader Sebastian Kurz triumphed in Sunday's parliamentary election, as widely expected, but he will need a coalition partner to form a stable government and the vote left him several options across the political spectrum.
The election followed the collapse in May of Kurz's coalition with the far-right Freedom Party (FPO) after a video sting scandal that forced FPO Vice Chancellor Heinz-Christian Strache to step down.
Kurz, 33, has been largely unscathed by the scandal, even gaining voters from the FPO as its support has slipped to roughly a fifth of the electorate from a little more than a quarter in the last vote in 2017.
As predicted by opinion polls for months, Kurz's People's Party (OVP) came a comfortable first, with 37.2 percent of the vote, according to a projection by pollster SORA for national broadcaster ORF published soon after voting ended.
The Social Democrats came second with 22.0 percent, well ahead of the far-right FPO on 16.0 percent and the resurgent Greens on 14.3 percent, the projection showed. It has a margin of error of 1.8 percentage points.
"We are very confident. We have a clear goal, namely to come first in this election. We want to improve our result," Kurz told reporters before casting his vote in Vienna, referring to the 31.5 percent his OVP achieved in the last election in 2017.
Kurz has said he will talk to all parties if he wins the election. His two most likely choices are either to ally with the FPO again or with the Greens and liberal Neos. A centrist coalition with the Social Democrats is possible but unlikely under their current leadership.
Surveys suggest the environment is voters' top concern, which has lifted the Greens from less than 4 percent of the vote at the last election, when they crashed out of parliament.
While they might be able to give Kurz and his party a narrow majority, he is unlikely to want to be at the mercy of a small number of its left-wing lawmakers. That means that if he does ally with the Greens he will probably seek a three-way deal including the liberal, pro-business Neos, who are on 7.4 percent.
It could take time for the Greens and Kurz to convince their supporters about working with each other. Many Greens voters see Kurz as their enemy since he brought the far-right to power. Many of Kurz's core voters, such as farmers and big business, are wary of the left-wing Greens.
As the campaign wound up last week, the FPO sought to focus attention on its core issue of migration, railing against immigrants in general and Muslims in particular, rather than addressing recent scandals that have eroded its support and could hurt Kurz's image if he allies with the FPO again.