On Thursday, the 275-seat National Assembly approved, with 180 votes, the list of names put forward by Shia Prime Minister Ibrahim al-Jafari, ending a power vacuum that has existed since 30 January.
The government's formation came on the 68th birthday of ousted ruler Saddam Hussein.
Delays in forming the cabinet, caused by disagreement over the allocation of ministries, have undermined Iraqis' faith in their leaders.
The drawn-out talks over the cabinet erased much of the optimism created by the elections and may have spurred on the uprising.
The cabinet will consist of 32 ministers and four deputy prime ministers, an effort to accommodate almost all Iraq's ethnic and sectarian groups.
Most of the posts went to Shia Muslims, the majority in the country and the new political power after decades of Sunni-led rule under Saddam.
Al-Jafari allocated most of the
cabinet posts to Shia Muslims
Kurds and Sunni Arabs were also strongly represented. Seven ministries went to women.
However, al-Jafari failed to name permanent ministers to five ministries - oil, defence, electricity, industry and human rights - underlining just how divided the new leaders are over the shape of the government.
The acting oil minister will be Ahmad Chalabi, a Shia once close to the Pentagon, and the acting defence minister will be al-Jafari.
The Interior Ministry, considered essential to security, went to Bayan Jabbur, a Shia, and the Finance Ministry will be headed by Ali Abd al-Amir Allawi, also a Shia.
The appointments led to Sunni groups withdrawing from the government.
Vice-President Ghazi al-Yawir, a Sunni, said the lineup was a sectarian carve-up. "We're not happy, but we have to wait until all the nominations are permanent before we do anything."
The Front of Sunni Arab Blocs (FSAB), which includes the Front of National Blocs (FNB) and National Dialogue Council (NDC), announced its withdrawal from the new Iraqi government line-up, NDC spokesman Salih al-Mutlaq said in a news conference.
"We notified al-Jafari about our decision to withdraw nominees since the announcement of the government has not coped with what we have agreed upon with al-Jafari," al-Mutlaq said.
Allawi walked out of talks and
is forming the opposition group
The Sunni bloc demanded seven key ministerial positions including defence minister and deputy prime minister.
"The number of ministerial portfolios [offered to the Sunni bloc] and their qualities are all below the required standard," said al-Yawir.
But he agreed this was "only the first step, not the end of the world".
But al-Mutlaq reiterated that the bloc would remain out of the cabinet unless al-Jafari appointed Sunni bloc members to some of the vacant posts.
Mishan al-Jaburi, a Sunni member of parliament called it a conspiracy against the Iraqi people.
"The conspirators are those who formed the government," he said.
No members of Iyad Allawi's party were included. Talks with the former interim prime minister broke down this week after he was said to have demanded too many cabinet posts.
Allawi's party came third in the elections, winning 40 seats in parliament, and will now form the rump of an opposition.
As well as having to tackle violence and rampant organised crime, the new government, working with parliament, will oversee the writing of a permanent constitution.
Iraq will hold fresh elections under the charter in December.
No progress has been made on the constitution, despite parliament's meeting on and off for more than a month. The document has to be drawn up by mid-August and then put to a referendum before elections are held.
If it does not look like it is going to be drafted on time, legislators can ask for a six-month extension before 1 August.