The 22 participant bishops must appoint the successor of Patriarch Raphael Bidawid, who died on July 7.
"After years of marginalization and absence from social life, the Chaldean Catholic community, under the guidance of the new patriarch, wishes to contribute to the future of Iraq," Vatican Radio explained, when reporting on today's event.
Some Christians fear that radical Shiites are exerting pressure to establish an Islamic theocracy in postwar Iraq.
There are 800,000 Christians in Iraq, constituting about 3% of the population. Among them, Chaldean Catholics constitute over 70%. The See of the Chaldean Patriarchate and the largest Chaldean community are in Baghdad, numbering more than 350,000 faithful.
The Chaldean Church is dedicated particularly to catechesis, education and aid to the Christian and Muslim poor.
The official language of Chaldean liturgy is Aramaic. There are Chaldean communities of the diaspora in America, Europe and Oceania. In 2000, a representation of the Chaldean Church before the Holy See was instituted in Rome.