Reading the text of his oath, the President promised to use all within his power to serve the country, nation and the Islamic establishment of Iran.
The ceremony was attended by ranking officials, including the head of the Supreme Leader's Office, the heads of the three branches of power, members of the Parliament, members of the Assembly of Experts, the incumbent cabinet members, the secretary and members of the Guardians Council, Friday prayer leaders, army officials and ambassadors of foreign countries to Iran.
Supreme Leader of the Islamic Revolution Ayatollah Ali Khamenei officially endorsed Ahmadinejad's presidency for the second term in a ceremony held at the Imam Khomeini Hosseiniyeh (Mosque) in downtown Tehran on Monday.
Judiciary chief Ayatollah Mahmoud Hashemi Shahroudi accompanied President Ahmadinejad while he took the podium to take oath as Iran's next president.
President Ahmadinejad has two weeks to introduce his new cabinet members after taking oath in the Majlis. More than 320 domestic and foreign reporters, photographers and journalists covered Ahmadinejad's swearing-in ceremony live.
Image: Mahmoud Ahmadinejad reads the oath of office as Judiciary Chief Mahmoud Hashemi Shahroudi and Parliament Speaker Ali Larijani watch
Photograph: Raheb Homavandi/Reuters