The election held on Saturday is the first since the defeat of Islamic State, with the capture of its de facto capital Mosul, last year.
A coalition linked to Shia religious leader Muqtada al-Sadr is the current frontrunner, with an alliance of candidates with ties to Iraq's Shia militia a close second.
After a vote Saturday that saw a record number of abstentions, the Victory Alliance of Prime Minister Haider al-Abadi, who has been backed by the global community, looked to have won in only one province. While many disillusioned Iraqis boycotted the vote, Mr Al Sadr's supporters could be relied upon to mobilise, said senior research fellow at London-based think tank Chatham House Renad Mansour.
Nevertheless, the terrorist group appears to still maintain an active presence in certain part of northern and western Iraq.
The early results reported late on Sunday suggested that Al-Sadr's bloc was ahead.
The head of the list is Hadi al Ameri, a long-time ally of Tehran, whose forces ended up battling alongside the United States to oust the militants.
Sadr has reinvented himself as an anti-graft crusader after rising to prominence as a powerful militia chief whose group waged a bloody insurgency against United States forces after the 2003 invasion. Iraqi pundits thought voters would flock to the polls for the first big election since the demise of ISIS in Iraq. Winning the largest number of seats does not automatically guarantee that, however.
"What matters now is post-election alliances", said Balsam Mustafa, an Iraq expert and PhD candidate in Modern Languages at the University of Birmingham.
His statement, which sparked criticism by Iraqi figures, was referring to the electoral alliance between Sadr, the Iraqi Communist Party and other secular groups who joined protests organised by Sadr in 2016 to press the government to see through a move to stem endemic corruption.
In 2017, Iraqi jets carried out at least one strike on IS targets in Syria, also in coordination with the US-led coalition and with the approval of the Syrian government.
Initial results indicate that the Sairoon coalition won between 54 and 56 out of 328 parliamentary seats, followed by the Al-Fatih bloc (between 40 and 44 seats) and the Al-Nasr bloc (between 40 and 42 seats), according to a source at Iraq's official electoral commission.
Regardless of the final result, there appears set to be prolonged horse-trading between the principle political forces earlier than any new premier and authorities might be put in. Despite that, al-Sadr's sophisticated political machine mobilized his loyal base of followers to go to the polls.
Instead, former Prime Minister Nouri Al Maliki was able to remain in power by forming a majority government with other blocs. Almost 2,600 women ran for office this year.