Iraq's western province of Anbar is torn by fighting as Sunni Muslim militants battle the Iraqi military. Its economy is struggling and Maliki faces criticism he is aggravating sectarian splits and trying to consolidate power.
Polls opened with a vehicle curfew in Baghdad. Voters were choosing from among 9,012 candidates and the parliamentary election will effectively serve as a referendum on Maliki, a Shi'ite Muslim who has governed for eight years.
The elections went off in central and southern Iraq with few hitches by mid-day, while turnout was low in Sunni regions, where residents are often afraid of the security forces and al Qaeda inspired militants.
The disparities were a reminder of the deep frictions now between the country's Shi'ite majority and Sunnis. Baghdad was quiet through late morning. Roads were dotted with military checkpoints and people walked on foot to the polling stations.
Humvees flanked the voting centres. Razor wire sealed off the area as people passed multiple checkpoints to go inside to vote. The seeming calm was a contrast to the 2010 elections.