Iraqi Prime Minister Nouri Maliki has hailed a peaceful vote for new provincial councils across the country as a victory for all Iraqis.
The BBC reports voting was extended by one hour due to a strong turnout, including among Sunnis who boycotted the last polls.
It was the first nationwide vote in four years and was seen as a test of stability before a general election due later this year.
Thousands of soldiers and police were deployed around polling stations.
After casting his vote in Baghdad, Mr Maliki said: "This is a victory for all Iraqis."
In a televised address, he said: "The purple fingers have returned to build Iraq."
He was referring to indelible ink stains on index fingers that show voters have cast their ballots. Earlier, he said it was a victory for all Iraqis.
Earlier, he said a high turnout would be an indicator of "the Iraqi people's trust in their government and in the elections" and "proof that the Iraqi people are now living in real security".
The Defence Ministry says the election was "a great success, like a wedding."
The elections are were held in 14 of the 18 provinces, with more than 14,000 candidates competing for 440 seats. Up to 15 million people were eligible to vote.
Councils are responsible for nominating provincial governors.
Early results are expected on Tuesday though the final result will take some time.
There is no voting in the three provinces of the Kurdish region and the ballot has been postponed in Kirkuk province.
Provincial councils are responsible for nominating the governors who lead the administration and oversee finance and reconstruction projects.
A major security operation was in force for the event.
Borders were closed, traffic bans were in place across Baghdad and major cities, and curfews were introduced.
Voters had to pass through stringent security checks to reach polling stations. Hundreds of women were recruited to help search female voters.
Fewer than 2% voted in the previous election in 2005, due to a boycott by Sunnis.
US President Barack Obama hailed the poll as an "important step forward" for Iraqi self-determination, saying: "I congratulate the people of Iraq on holding significant provincial elections today."
Mr Obama opposed the Iraq war. In a statement, he praised technical assistance by the United Nations and other organisations to the electoral commission, which he said "performed professionally under difficult circumstances".