Ali Reza Afshar, deputy interior minister, described the turnout as "glorious".Polls had opened at 8am (0430 GMT), with state radio announcing that "today, the Iranian nation once again will show its political maturity".
Al Jazeera's Teymoor Nabili in Tehran said that the government had been very keen to ensure a high turnout.
"They were making it as easy as they possibly could for people to get to the voting booths and cast their ballots," he said.
"The opinion of the public in Iran has been very wideranging, some refusing to vote because of what they see as irregularities, others coming out to vote and hoping that they can make a difference."
Ahead of the vote, the Guardian Council, an unelected body of clerics and jurists, disqualified around 1,700 candidates, mostly reformists.
Those barred from running were judged "insufficiently loyal to Islam or the revolution".
The Reformists acknowledged ahead of the vote that that the disqualifications meant that they could contest just half the available seats, leaving a clear run for conservatives to retain control of the 290-seat chamber.
However, Mahmoud Ahmadinejad, Iran's president, dismissed complaints that the system was stacked against the Reformists.
"Parliament belongs to the people and it should be a reflection of what they want," he said after voting.
Ayatollah Ali Khamenei, Iran's supreme leader, effectively pledged his support for the conservatives on Wednesday.
In a speech, he called on voters to back candidates who are opposed to the US and "whose loyalties are to Islam and justice".
The United States, which has been at odds with Iran since the Islamic revolution in 1979, criticised the electoral process.
"In essence the results are cooked ... in the sense that the Iranian people were not able to vote for a full range of people," Sean McCormack, US state department spokesman, said.
The election had been seen by many as a test of the Ahmadinejad's popularity ahead of presidential elections in 2009.
|The elections was seen by many as a test of |
Mahmoud Ahmadinejad's popularity [AFP]
The president has been accused of failing to control inflation, which has risen by 20 per cent, and increasing tensions over Iran's nuclear ambitions.
Sanctions imposed by the United Nations over the country's nuclear programme have weakened Iran's social structure and many are finding it hard to earn a living.
"The economy is the issue. I will vote for those who can sew up the hole in my pocket," Ali Mashallahi, a government employee with three children, said before voting.
But despite Ahmadinejad's problems several politicians opposed to him told the Reuters news agency that their informal exit polls suggested the United Front, the most pro-government group of candidates, was doing well in Tehran.
Conservatives held 26 of the capital's 30 seats in the outgoing assembly.