Iranian President Mahmoud Ahmadinejad arrived in Cairo on Tuesday, in the first visit by an Iranian head of state to Egypt in more than 30 years.
He was received at Cairo airport by Egyptian President Mohammed Morsi.
Ahmadinejad is leading the Iranian delegation to a summit of the Organization of Islamic Cooperation, which starts in the Egyptian capital on Wednesday.
Before that, the president of the largest predominantly Shiite Muslim state is to meet Egypt's top Sunni cleric, Ahmed al-Tayyib, sheikh of the al-Azhar Sunni Islamic institute.
Ahmadinejad is also expected to visit the al-Hussein mosque in central Cairo and the Giza pyramids.
Iran and Egypt severed diplomatic ties after Iran's 1979 Islamic revolution and Egypt's peace treaty with Israel. Iran does not recognize Israel.
Since Egypt's 2011 revolution that toppled president Hosny Mubarak, Iran has actively sought to improve relations.
Morsi visited Tehran in August to attend a conference of the Non-Aligned Movement.
Egypt remains cautious about re-establishing full diplomatic relations with Iran, apparently wary of estranging oil-rich Gulf countries that have repeatedly accused Tehran of stirring unrest in the region.
Egypt and Iran are also at odds over Syria's nearly two-year conflict that has claimed at least 60,000 lives.
Tehran, an ally of Damascus, has backed Syrian President Bashar al-Assad's crackdown on the opposition. Morsi has repeatedly called for al-Assad to step down