ElBaradei is being accompanied on the trip by Olli Heinonen, a deputy director-general of the International Atomic Energy Agency.
Elbaradei will hold discussions on Tehrans controversial nuclear program with top Iranian officials including hard-line President Mahmoud Ahmadinejad, who he is expected to meet on Saturday, Iranian Foreign Minister Manouchehr Mottaki, and chief nuclear negotiator Saeed Jalili.
ElBaradei was greeted at the airport in Tehran by Mohammad Saeedi, deputy head of the Atomic Energy Organisation of Iran, and a host of other nuclear officials.
