Election officials, however, said there were no major violations.
He said: "We recorded widespread violations in many forms ... Some pro-government parties were giving bribes of between 4,000 and 20,000 drams ($11-$56) right in front of polling stations."
"We can say that we had a positive election," Garegin Azarian, chairman of the central elections commission, said.
Azarian said: "The election was held in a calm atmosphere and in compliance with the law."
Armenia does not have a history of free and fair elections.
No vote has been declared fair since 1991, when this small, mountainous republic became independent after the collapse of the Soviet Union.
A flawed election, this time, could cost the country dear, where more than 30 per cent of people already live on less than $2 a day.
US officials have said the provision of $235 million in aid to Armenia under the Millennium Challenge Fund would be threatened if the vote is deemed unfair.
Opposition parties have vowed to organise street demonstrations on Sunday in an attempt to overturn the results if fraud was suspected.
Surveys show Armenians are hungry for reform, with an overwhelming majority supporting radical change, but polls predicted pro-government parties will come out ahead in the election.
Initial results from 15 of Armenia's 41 polling districts showed the ruling Republican Party in the lead, the Armenian news agencies reported.
Preliminary figures showed voter turnout at 59.4 per cent, the elections commission said after polls closed.
About 2.3 million of Armenia's three million people were registered to vote for 131 seats in parliament.
Hundreds of local and international observers were monitoring the vote, including more than 300 from the Organisation for Security and Cooperation in Europe, which was to issue a report on the election on Sunday.
No vote has been declared fair since Armenia gained its independence in 1991 [AFP]
The vote was also a dress rehearsal for a presidential election next year at the end of the second term for Robert Kocharian, Armenia's president.
Serzh Sarkisian, the prime minister and Kocharian's chosen successor, is expected to use the parliamentary vote as a springboard to launch his presidential campaign.
More than 20 opposition parties were running and analysts say these divisions weaken chances of defeating Armenia's two pro-government parties.
The parties are Sarkisian's Republican Party and the Prosperous Armenia Party, headed by Gagik Tsarukian, a millionaire and former world arm wrestling champion.