Jumana al-Ghalai, spokeswoman of the Independent High Electoral Commission, said in a statement that polling centres across Iraq opened at 7 a.m., reports Xinhua news agency.
The voting process will end at 6 p.m., she added.
More than a million voters from the security forces are scheduled to cast their ballots at 595 polling centre across the country, and more than 120,000 displaced people will vote in 86 polling centre during the day.
The Iraqi parliamentary elections, originally scheduled for 2022, were advanced in response to months of protests against corruption and a lack of public services.
According to the electoral commission, about 24 million Iraqis are eligible to cast their ballots for 3,249 candidates, running individually and within 167 parties and coalitions, vying for 329 seats in the legislature.