The list that won the most seats in the previous election was the United Iraqi Alliance, made up primarily of religious Shi'ite parties. United Iraqi Alliance won 128 out of the then 275 seats being contested. However this list split into two lists for this election into the State of Law Coalition of Prime Minister Nouri al-Maliki and the National Iraqi Alliance, which includes most of the other parties.

The National Iraqi Alliance started to take shape in August 2009, and is made up of the principal remaining components of the Alliance: SIIC, the Badr Organization, the Sadrist Movement, the National Reform Trend, and the Islamic Dawa Party - Iraq Organization, and former deputy prime minister Ahmad Chalabi.

In September 2009, the State of Law Coalition was formally announced without the Islamic Dawa Party. Another member of the State of Law Coalition is the Basra-based Islamic Virtue Party, which had left the United Iraqi Alliance soon after the December 2005 election.

The Kurdistani Alliance proposed a single pan-Kurdish list, including the Islamist parties and the Movement for Change, which had gained a quarter of the seats in the Iraqi Kurdistan legislative election of 2009. However, the Movement for Change said competing separately would “secure their own powers” in Baghdad. The Kurdistan Islamic Union also said it would compete separately, as it had in December 2005, and also decided against a pan-Islamist coalition with the Islamic Movement of Kurdistan and the Kurdistan Islamic Group.

The main Sunni Arab party, the Iraqi Islamic Party, was hit by high profile defections including Vice-President Tariq al-Hashimi, who launched a new party called the Renewal List. Another parliamentarian, Omar Abdul Sattar, left the party in early 2009 and formed a coalition called the Iraqi National Movement with the Iraqi National List of former Prime Minister Iyad Allawi and the neo-Baathist Iraqi National Dialogue Front led by Saleh al-Mutlak.

Ahmed Abu Risha, the head of the Awakening movement party that won the most seats in the Al Anbar governorate election, 2009, formed a coalition with Interior Minister Jawad al-Bolani's Iraqi Constitutional Party and Ahmed Abdul Ghafour al-Samarrai's Sunni Endowment called Iraq's Unity.