Iraqis are voting in the first parliamentary elections since the government declared victory over the so-called Islamic State (IS) last year.
Reports say about 7 000 candidates from rival coalition alliances are vying for seats in the 329-member assembly.
Iraq is still struggling to rebuild itself after four years of war against IS.
Whoever wins will need to keep Iraq’s fragile unity in the face of sectarian and separatist tensions.
Polls across the country opened in the morning and are due to close this evening.
Iraqis can vote for rival lists of candidates most of which are predominantly Shia or Sunni, though the Kurds have their own lists.
The Shia-led government has won praise for the fight against IS militants, and security has vastly improved across the country, but many Iraqis are disillusioned by widespread government corruption and a weak economy.
The vote also comes just days after US President Donald Trump pulled out of the Iran nuclear deal.
Some Iraqis fear their country could once again become a casualty in any struggle between America and Iran.