Talabani said on arrival that his country needs Iran's "comprehensive help to fight terrorism, restore security, and stabilize Iraq."
Talabani is due to have talks with Iran's Supreme Leader Ayatollah Ali Khamenei on November 29.
His trip comes as authorities in Baghdad lifted the city's curfew today and reopened the international airport. Talabani had been scheduled to fly to Tehran on November 25.
The curfew was imposed following bombings that killed more than 200 people last week.
Fresh violence was reported as traffic returned to Baghdad's streets.
In central Baghdad, gunmen opened fire on a crowded street, killing six people. In a southern district, armed men in two cars attacked a police patrol, wounding six officers.
Earlier, the U.S. military said one of its fighter jets crashed in Iraq with one pilot aboard. The F-16 was supporting coalition ground forces when it crashed northwest of Baghdad.
There was no information about the cause of the crash or the fate of the pilot.
(Reuters, AFP, AP)