Polls show Prime Minister Nikol Pashinyan's ruling Civil Contract party leading, backed by up to 32 per cent of voters, with the pro-Russian Strong Armenia party in second place with up to 11 per cent.
Pashinyan has moved Armenia closer to the West since coming to power in 2018, and away from traditional patron Russia, which has provoked Moscow's ire in the lead-up to the vote.
GDP per capita has also doubled under Pashinyan, a journalist and opposition activist turned politician.
"I really like how Armenia has been growing right before my eyes," 39-year-old voter Karine Darbinyan said at a rally for Pashinyan in Yerevan's central square on Friday.
Pashinyan has faced a wave of criticism from the opposition and some sections of the public who have accused him of capitulating to Azerbaijan, particularly since the 2023 war.
He has countered by placing his peace effort centre stage in his campaign, above all the agreement he signed at the White House in August with Azerbaijan after an on-and-off war that has raged since the late 1980s.
Armenia's opposition is dominated by pro-Russian groups including Strong Armenia, formed in 2025 by Russian-Armenian billionaire Samvel Karapetyan.
Karapetyan wants to keep Armenia close to Russia, a key supplier of energy and buyer of exports.
At a Strong Armenia rally in Yerevan last week, a woman who gave her name only as Gayane said she supported Karapetyan because he would ensure "that our Armenia remains Armenian".
She said her roots were in Nagorno-Karabakh, the breakaway territory inhabited by ethnic Armenians that Azerbaijan retook in the 2023 war.
The region's entire Armenian population fled after the chaotic one-day lightning offensive.
"We lost Artsakh, hoping it would remain with us," Gayane said, using a historic Armenian name for the territory.
"The current authorities have taken away that hope from us. And Samvel Karapetyan has now given us new hope that we can at least preserve our Armenia and our traditions."
Critics and rights groups have accused Pashinyan of authoritarianism after many of his opponents have been jailed in recent years.
The government has broadly defended the actions of law enforcement agencies against individuals whom it says are trying to foment coups.
A spate of arrests in the lead-up to the vote targeted the opposition, including parliamentary candidates for the Strong Armenia party.
Some 2.48 million people are registered to vote in the landlocked country of three million.